I'm using waves with giga. Giga didn't like my older waves stuff. (2.xx) It would actually restart the computer upon trying to boot giga. I believe it was the VST shell that was the problem. Now I'm using the newer waves diamond (4.xx) without any trouble. Of course, I went ahead and installed the waves vst shell stuff into its own folder. And I'm not pointing the giga plug-in manager to that folder. Seems to be working fine. Let me know what you come up with. Do you have waves? What version? How are you running them? (DX, VST, RTAS)
I'm from the south and we're both religious and superstisious. That's my reasoning for the VST shell thing. When troubleshooting one of the tech guys had suggested Giga mighta been havin' conflicts with a VST. Not so sure that was the case, but you never know. That was something I did as a precaution along the way. At one of my partner studios we use the VST with wavelab/nuendo as well. I personally have Sonar and Sound Forge at my studio here at the house and use the DX with those. I saw in another post unchecking monitor file activity helped you. (helped me as well) Are you still having Waves/Giga problems?
I just upgraded to Orchestral version and it came with add. info stating certain 3rd party plug-ins to not point giga to. Waves isn't one of them, but my point is maybe there's something to not even pointing it out to giga. (maybe not). My previous waves was ilock, not this one.
Good luck, I hate it when two of the best programs don't work together.