Did you happen to be married? If that is the case, your former wife will probably gloat over your decision to go MAC.
You could try to export uncompressed from a stable PC, import into the handicapped MAC and try from there.
Not a helpful answer Harm, but thanks for the humor anyhow. Stable PC??? What's that? The whole reason I switched to Mac was because Windows 7, XP, Vista, etc., are not stable. Personally, I've never seen a Mac get a BSOD, or anything other screen of death. Don't be a hater.
The only times I have seen BSOD's with Win7 was when pushing the limits with overclocking. XP and Vista were not as stable, I admit that.
OTOH, with around 20 times more PC users than there are MAC users, the number of questions here from MAC users does not inspire confidence. But that is another topic.
In some way you need to get your old projects available for the MAC. You can try exporting to QuiRcktime from the PC, or use a visually lossless or uncompressed format and try to import that into the MAC.