I had Vegas Audio 2.0d working perfectly with DirectX 7 and I installed DirectX8a, verified it wasn't causing any problems with Vegas 2.0d or any other audio programs and then made the mistake of "upgrading" to Vegas Audio 2.0g. As it opens and scans for plug-ins it gives an illegal error from Rundll32 but it still opens. Only problem is I have no DirectX effects any more. Fortunately I had activated GoBack before doing all this and was able to go back to my working Vegas 2.0d and DirectX 7 with one mouse click. I keep telling myself not to mess with a working installation but do I ever listen? Apparently not : )