Invisible or missing character/sprite in MAME games?

[hawkfanz]

I have a lot of MAME games that seem to make the character go invisible for a short period of time at certain times in the game.  I think it is usually when the character gets hit.  For example in TMNT when the turtle would usually be flashing I don't see the turtle at all.  Seems strange that they just aren't on the screen for a few seconds.  Is this a bad game file or do I need to tweak my HLSL settings?  Thanks for the help!