Audio Problems

I'm going nuts. Part of the sound reproduction from FS9 has stopped. Sometimes I can get it started again, but most of the time, the ATC and pilot voices are lost in a high static background.Here's what happened (I think). I installed FSX on my P4 2.5GHz Dell box (2G Ram, ATI Radeon 9550/x1050 256K Video Card, Creative SD Live! 24 bit sound card). Several more simple applications ran fine under FSX (i.e., the Cal Classic DC6), but when I installed the new PMDG 744 app, the performance wasn't what I expected. So after reading the FSX readmes and before uninstalling the 744 and FSX, I applied the update that came with the FSX 744 to my installed FS9 744 and 744F. This resulted in several problems with the FS9 apps. Some of the instruments were blank and excess static would appear during FS9 744 flights. I uninstalled and reinstalled the FS9 PMDG products. This fixed the instrument (clock) problem, but it didn't clear up the sound. When the static started, all I could hear was the engine sound and that was full of static.I finally uninstalled the FSX 744 and FSX itself. I still had the problem with the FS9 744 and all the other FS9 apps. So I uninstalled and reinstalled FS9 and the PMDG apps. My sound still had the same problems. I updated the codecs with K-Lite which solved the sound problem until I fired up the FS9 744. It seems that when I pause the app, the sound goes into the tank. The problem then moved to every other plane.I'm now stuck and I'm hoping someone can point me in the right direction, or at least suggest something. I've updated all my drivers, but I did read elsewhere that others had problems with the SD Live! card.I'm going to pull the card out and try another install. If that doesn't work, then it's f-disk time and a total rebuild. But I rather not go thru all that work. Thanks in advance,Jim Driskell