This has also been reported in a lot of old NES games and had to be fixed, but essentially, here's this one:

http://youtu.be/0KvENHGY_lk

Basically, the flickering Wizzrobes stay totally invisible at times on HD computers like Windows 7. This may not normally be an issue, but when playing ROMhack style quests with high damage, this shows up quite brutally and causes unnecessary hits and makes the levels unplayable. Is there any way this can be fixed?

-James