I'm getting the same bug. No sounds from IC whatsoever. Also, my reactor doesn't work. It's not putting out any energy.
The only other mod I'm using is TMI.
Forge is at 4.1.1.
MCPatcher log is showing:
Display Spoiler
Error in class 'SourceLWJGL OpenAL'
2012-09-18 02:01:33 [INFO] [STDOUT] Channel null in method 'stop'
2012-09-18 02:01:33 [INFO] [STDOUT] Error in class 'SourceLWJGL OpenAL'
2012-09-18 02:01:33 [INFO] [STDOUT] Channel null in method 'stop'
2012-09-18 02:02:04 [INFO] [STDOUT] Error in class 'SourceLWJGL OpenAL'
2012-09-18 02:02:04 [INFO] [STDOUT] Channel null in method 'stop'
2012-09-18 02:02:04 [INFO] [STDOUT] Error in class 'SourceLWJGL OpenAL'
2012-09-18 02:02:04 [INFO] [STDOUT] Channel null in method 'stop'
2012-09-18 02:02:58 [INFO] [STDOUT] Error in class 'SourceLWJGL OpenAL'
2012-09-18 02:02:58 [INFO] [STDOUT] Channel null in method 'stop'
2012-09-18 02:02:58 [INFO] [STDOUT] Error in class 'SourceLWJGL OpenAL'
2012-09-18 02:02:58 [INFO] [STDOUT] Channel null in method 'stop'
2012-09-18 02:04:27 [INFO] [STDOUT] Error in class 'SourceLWJGL OpenAL'
2012-09-18 02:04:27 [INFO] [STDOUT] Channel null in method 'stop'
2012-09-18 02:04:27 [INFO] [STDOUT] Error in class 'SourceLWJGL OpenAL'
2012-09-18 02:04:27 [INFO] [STDOUT] Channel null in method 'stop'