I have recently purchased the PMDG 737-6,7,8,& 900. I have been flying the tutorials and learning the systems for the last several days & nights. I had something happen twice in the last few days that I had never seen before. I was online, finished with my preflight, did an engine start, but no engine sounds. I checked my settings, they were OK. Shut down MSFS and restarted with the same results. I could load a default plane and it would be fine but not the PMDG. Downloaded the latest FSUIPC, installed it, still no engine sounds. I then removed all the addon modules, with the exception of the FSUIPC. I remembered that I had had a lockup at the end of my prior flight; I thought that the FS9 might be corrupt so I uninstalled MSFS to start over. (I found out afterward that I could just move the FS9.cfg file out and MSFS would create a new one, so what is 3-4 wasted hours doing something that was completely unnecessary when you are learning valuable lessons?) When I get it all reinstalled and back up with everything configured, its fine. Last night I get ready to go again and the same thing happened only this time I did not have SB3 loaded only servinfo. Just so happens I had zipped up the 600-700 aircraft files to backup just before I upgraded to the 800-900 package, so I pulled the sound out of the zipped 700 and copied to current 700 and I'm back in business. The only thing that I can come up with is that something else that I am running is corrupting the panel.cfg file. I have never experienced that before and it happened 2 times in 3 days. Has anyone else had a similar problem? Any help that you could offer would be appreciated.P4-3Ghz / SBLive24 / 1GB Ram DDR2 / Nvidia 6800-PCI-Express 16X-256mb / WinXPHome / Dual Monitors / CH USB YokeMSFS9.1 / SB3 / F1view / Servinfo / ADVDisplay

The same thing happened again, no engine sounds. I went into SB3 and my voice communications were not audible either so I uninstalled SB3, deleted the folder, and reintalled it. Restarted my computer and it is now fixed. I was a SB3 problem, not a PMDG problem. Just thought I would I would wrap this post up in case someone else has a similar problem. Thanks