Flash displays on some windows machines, not others

just having some strange behavior with my flash movie. I’d post it here, but i don’t think the movie is at fault. I have tested the movie on ff (linux, mac, windows), ie, and safari. everything seemed to be fine. then one user tried to view it from his windows machine, and he had problems in both ff and ie. it was almost as if the flash movie was not transparent (the flash div overlays an html div.) and yes, i did set wmode to transparent.

he is running xp, the newest flash, newest ff, and ie7. the other windows machines i’ve tested it on have the same.

any ideas why this would happen on one machine, but not others?

thanks for any help