Works perfectly for me, no changes required. (except including acknex.h)

Version A7.85.4 commercial.

The latest direct x drivers are installed, like I said it seems to be randomly working or not working based on whether or not a mouse farted in the past 15 minutes. Does camera angle have anything to do with this at all?

Just to let you know the sort of thing that I am talking about; just now I started up my project, deleted all the enemies placed around my level, then placed the same type of enemy around the level again, compiled it and it runs fine now; BEAM and STREAK work great.

Cant think of anything except if the camera is too close,
it may clip SOME of the particles, but some should remain...

Have you upgraded gamestudio above 7.07 yet?
It was a horribly buggy version...