Hi, I'm using pjsip 1.8.5 on Mac OS X 10.6. And I still have problems with plugging or unplugging headphones. When I run pjsua, establish a call and plug or unplug headphones, sound stops and there are many lines like that: 13:41:50.825 Master/sound Buffer size adjusted from 1280 to 992 (eff_cnt=920) 13:41:51.125 ec0x10060e980 Underflow, buf_cnt=5, will generate 1 frame 13:41:51.165 Master/sound Buffer size adjusted from 1312 to 1005 (eff_cnt=920) 13:41:51.485 ec0x10060e980 Underflow, buf_cnt=5, will generate 1 frame 13:41:51.525 Master/sound Buffer size adjusted from 1325 to 906 (eff_cnt=920) 13:41:51.805 ec0x10060e980 Underflow, buf_cnt=5, will generate 1 frame 13:41:52.065 Master/sound Buffer size adjusted from 1226 to 1040 (eff_cnt=850) 13:41:52.125 ec0x10060e980 Underflow, buf_cnt=5, will generate 1 frame 13:41:52.165 Master/sound Buffer size adjusted from 1360 to 1144 (eff_cnt=850) When I link my app against pjsip-ua and do the same as above, after several underflows app quits with an assertion: [...about 50 lines like the following underflows...] 13:40:11.758 ec0x115c1e520 Underflow, buf_cnt=0, will generate 1 frame 13:40:11.778 ec0x115c1e520 Underflow, buf_cnt=0, will generate 1 frame 13:40:11.798 ec0x115c1e520 Underflow, buf_cnt=0, will generate 1 frame Assertion failed: (thread->signature1 != 0xDEAFBEEF || thread->signature2 != 0xDEADC0DE || (thread->thread == pthread_self())), function pj_thread_register, file ../src/pj/os_core_unix.c, line 403. What could be the problem? Alexei