I've tried a number of SIP clients on my HTC Legend, including 3CX and SIPDroid. I've landed on CSipSimple as my client of choice for the time being. It works well and is in active development. I get the latest versions from the dev site hosted on code.google.com rather than from the market.
Cheers
Can you screenshot your config of your pbxinaflash and post what settings you ended up configuring in CSIPSIMPLE? I got it to register and make calls but I get this odd issue and the call never terminates or sometimes I don't see anything in the CLI on my asterisk at all. Like the phone isn't even trying. I'm going to blame CSIPSIMPLE as I have a wifi phone connected to that extension that worked fine from the same wifi network. I can't see logs to diagnose the phone side though.
It stops working around the Packet2Packet mark:
pbx*CLI>
pbx*CLI>
-- Executing [3708100@from-internal:1] Macro("SIP/3434-09e10138", "user-callerid|SKIPTTL|") in new stack
-- Executing [s@macro-user-callerid:1] Set("SIP/3434-09e10138", "AMPUSER=3434") in new stack
-- Executing [s@macro-user-callerid:2] GotoIf("SIP/3434-09e10138", "0?report") in new stack
-- Executing [s@macro-user-callerid:3] ExecIf("SIP/3434-09e10138", "1|Set|REALCALLERIDNUM=3434") in new stack
-- Executing [s@macro-user-callerid:4] Set("SIP/3434-09e10138", "AMPUSER=3434") in new stack
-- Executing [s@macro-user-callerid:5] Set("SIP/3434-09e10138", "AMPUSERCIDNAME=Wifi Phone") in new stack
-- Executing [s@macro-user-callerid:6] GotoIf("SIP/3434-09e10138", "0?report") in new stack
-- Executing [s@macro-user-callerid:7] Set("SIP/3434-09e10138", "AMPUSERCID=3434") in new stack
-- Executing [s@macro-user-callerid:8] Set("SIP/3434-09e10138", "CALLERID(all)="Wifi Phone" <3434>") in new stack
-- Executing [s@macro-user-callerid:9] ExecIf("SIP/3434-09e10138", "0|Set|CHANNEL(language)=") in new stack
-- Executing [s@macro-user-callerid:10] GotoIf("SIP/3434-09e10138", "1?continue") in new stack
-- Goto (macro-user-callerid,s,19)
-- Executing [s@macro-user-callerid:19] Set("SIP/3434-09e10138", "CALLERID(number)=3434") in new stack
-- Executing [s@macro-user-callerid:20] Set("SIP/3434-09e10138", "CALLERID(name)=Wifi Phone") in new stack
-- Executing [s@macro-user-callerid:21] NoOp("SIP/3434-09e10138", "Using CallerID "Wifi Phone" <3434>") in new stack
-- Executing [3708100@from-internal:2] NoOp("SIP/3434-09e10138", "Calling Out Route: NormalOutbound") in new stack
-- Executing [3708100@from-internal:3] Set("SIP/3434-09e10138", "_NODEST=") in new stack
-- Executing [3708100@from-internal:4] Macro("SIP/3434-09e10138", "record-enable|3434|OUT|") in new stack
-- Executing [s@macro-record-enable:1] GotoIf("SIP/3434-09e10138", "1?check") in new stack
-- Goto (macro-record-enable,s,4)
-- Executing [s@macro-record-enable:4] ExecIf("SIP/3434-09e10138", "0|MacroExit|") in new stack
-- Executing [s@macro-record-enable:5] GotoIf("SIP/3434-09e10138", "0?Group:OUT") in new stack
-- Goto (macro-record-enable,s,15)
-- Executing [s@macro-record-enable:15] GotoIf("SIP/3434-09e10138", "0?IN") in new stack
-- Executing [s@macro-record-enable:16] ExecIf("SIP/3434-09e10138", "1|MacroExit|") in new stack
-- Executing [3708100@from-internal:5] Macro("SIP/3434-09e10138", "dialout-trunk|2|3708100|") in new stack
-- Executing [s@macro-dialout-trunk:1] Set("SIP/3434-09e10138", "DIAL_TRUNK=2") in new stack
-- Executing [s@macro-dialout-trunk:2] GosubIf("SIP/3434-09e10138", "0?sub-pincheck|s|1") in new stack
-- Executing [s@macro-dialout-trunk:3] GotoIf("SIP/3434-09e10138", "0?disabletrunk|1") in new stack
-- Executing [s@macro-dialout-trunk:4] Set("SIP/3434-09e10138", "DIAL_NUMBER=3708100") in new stack
-- Executing [s@macro-dialout-trunk:5] Set("SIP/3434-09e10138", "DIAL_TRUNK_OPTIONS=tr") in new stack
-- Executing [s@macro-dialout-trunk:6] Set("SIP/3434-09e10138", "OUTBOUND_GROUP=OUT_2") in new stack
-- Executing [s@macro-dialout-trunk:7] GotoIf("SIP/3434-09e10138", "1?nomax") in new stack
-- Goto (macro-dialout-trunk,s,9)
-- Executing [s@macro-dialout-trunk:9] GotoIf("SIP/3434-09e10138", "0?skipoutcid") in new stack
-- Executing [s@macro-dialout-trunk:10] Set("SIP/3434-09e10138", "DIAL_TRUNK_OPTIONS=") in new stack
-- Executing [s@macro-dialout-trunk:11] Macro("SIP/3434-09e10138", "outbound-callerid|2") in new stack
-- Executing [s@macro-outbound-callerid:1] ExecIf("SIP/3434-09e10138", "0|SetCallerPres|") in new stack
-- Executing [s@macro-outbound-callerid:2] ExecIf("SIP/3434-09e10138", "0|Set|REALCALLERIDNUM=3434") in new stack
-- Executing [s@macro-outbound-callerid:3] GotoIf("SIP/3434-09e10138", "1?normcid") in new stack
-- Goto (macro-outbound-callerid,s,6)
-- Executing [s@macro-outbound-callerid:6] Set("SIP/3434-09e10138", "USEROUTCID=") in new stack
-- Executing [s@macro-outbound-callerid:7] Set("SIP/3434-09e10138", "EMERGENCYCID=") in new stack
-- Executing [s@macro-outbound-callerid:8] Set("SIP/3434-09e10138", "TRUNKOUTCID=Justin<5xxxxx4>") in new stack
-- Executing [s@macro-outbound-callerid:9] GotoIf("SIP/3434-09e10138", "1?trunkcid") in new stack
-- Goto (macro-outbound-callerid,s,12)
-- Executing [s@macro-outbound-callerid:12] ExecIf("SIP/3434-09e10138", "1|Set|CALLERID(all)=Justin<5xxxxxx4>") in new stack
-- Executing [s@macro-outbound-callerid:13] ExecIf("SIP/3434-09e10138", "0|Set|CALLERID(all)=") in new stack
-- Executing [s@macro-outbound-callerid:14] ExecIf("SIP/3434-09e10138", "0|Set|CALLERID(all)=") in new stack
-- Executing [s@macro-outbound-callerid:15] ExecIf("SIP/3434-09e10138", "0|SetCallerPres|prohib_passed_screen") in new stack
-- Executing [s@macro-dialout-trunk:12] GosubIf("SIP/3434-09e10138", "1?sub-flp-2|s|1") in new stack
-- Executing [s@sub-flp-2:1] ExecIf("SIP/3434-09e10138", "1|Set|TARGET_FLP_2=5183708100") in new stack
-- Executing [s@sub-flp-2:2] GotoIf("SIP/3434-09e10138", "1?match") in new stack
-- Goto (sub-flp-2,s,4)
-- Executing [s@sub-flp-2:4] Set("SIP/3434-09e10138", "DIAL_NUMBER=5183708100") in new stack
-- Executing [s@sub-flp-2:5] Return("SIP/3434-09e10138", "") in new stack
-- Executing [s@macro-dialout-trunk:13] Set("SIP/3434-09e10138", "OUTNUM=5183708100") in new stack
-- Executing [s@macro-dialout-trunk:14] Set("SIP/3434-09e10138", "custom=SIP/vitel-outbound") in new stack
-- Executing [s@macro-dialout-trunk:15] ExecIf("SIP/3434-09e10138", "0|Set|DIAL_TRUNK_OPTIONS=M(setmusic^)") in new stack
-- Executing [s@macro-dialout-trunk:16] Macro("SIP/3434-09e10138", "dialout-trunk-predial-hook|") in new stack
-- Executing [s@macro-dialout-trunk-predial-hook:1] MacroExit("SIP/3434-09e10138", "") in new stack
-- Executing [s@macro-dialout-trunk:17] GotoIf("SIP/3434-09e10138", "0?bypass|1") in new stack
-- Executing [s@macro-dialout-trunk:18] GotoIf("SIP/3434-09e10138", "0?customtrunk") in new stack
-- Executing [s@macro-dialout-trunk:19] Dial("SIP/3434-09e10138", "SIP/vitel-outbound/5183708100|300|") in new stack
-- Called vitel-outbound/5183708100
-- SIP/vitel-outbound-09e17930 is ringing
-- SIP/vitel-outbound-09e17930 is making progress passing it to SIP/3434-09e10138
-- SIP/vitel-outbound-09e17930 answered SIP/3434-09e10138
-- Packet2Packet bridging SIP/3434-09e10138 and SIP/vitel-outbound-09e17930