No affect, unfortunately it's still slowing down when there's big explosions. I had no idea I could just create the missing folder though, I'd figured there was other stuff in it too and I'd somehow fudged up the installation process in the first place. Thanks for the info on that.
I guess I am gonna have to just ditch the Adveffects stuff. It's a bummer, it does seem to be ONLY the shockwave stuff that does it, otherwise it's been running in 1280x800 mode with all the effects turned on without any issues.
Then again, I AM running a Pentium M 1.7 with a Mobility X600 and a gig of RAM. That probably falls pretty short of what's required to run the adveffects stuff, huh? Oh well, thanks for the help anyways guys.