See through walls in missions and other weirdness

[Skyhawke]

So, I'm playing on a Mac and these may be mac only issues, but on some missions I get see through walls.  It's almost as if the wall's opacity is down to 60%.  You can still tell it's a wall so, it's not totally throwing me off, but it's definitely jarring.  Wentworths doesn't have transparency issues, but it's floor seems to be trying to render multiple times and the texture moves as I move.  Again, trifling and not a game breaker by any standard, but still weird. 

 

Anyone else have these issues?  I'm running graphics at max, btw.