Call never comes back from hold

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Dial or awnser a call
2. press the hold button
3. The hold music plays
4. When you press hold again the call never comes back

What is the expected output? What do you see instead?
The hold music should stop and the call should be back but insdead 
the hold music keeps playing.

What version of the product are you using? On what operating system?
1.3.5 Android 2.0

Which SIP server are you using? What happens with PBXes?
I connect to extention on an asterisk 1.6 server. the previous version 
worked fine. This started after the upgrade to 1.3.5

Which type of network are you using?
I use Verizon 3g & Wifi it happens on both

Please provide any additional information below.
I have tested other sip clients on the phone and it works fine with the 
same extention. 

Good work on sipdroid I really like your app.

Thanks

Original issue reported on code.google.com by wheelerw...@gmail.com on 23 Jan 2010 at 4:00

[GoogleCodeExporter]

hi, I also have the same issues, I found another problem:
1. A call B, if on A phone, press the hold button;
2. It works for around 22 seconds(there is a 
timeout of 22 seconds no RTP received the call gets hung up); B phone hung up, 
but A phone will keep the hold status;
3. A call B, if on B phone, press the hold button, it cant work;

Original comment by starhubp...@gmail.com on 6 Sep 2010 at 2:50