I'm having the same problem. I'm trying to get Medialab to play some short .wmv files (tv ads). I've inserted them as movie items in questionnaires. But when I try to run the questionnaire, a black rectangle appears, turns to white, then Medialab just freezes - video doesn't present and I have to use windows task manager to get out of Medialab. I've checked and the videos do play in Windows Media Player with no problem. I tried the workaround mentioned above and it doesn't make any difference. I'm running Medialab 2006.2.40

Please help! Thanks.