[Wine] Need help with Morrowind graphical glitch

[Arche]

Hi, I've posted this question over on the porting team forum, but so far no one has been able to help, and I'm hoping that some people with lots of experience with wine might know more. I'm trying to play Morrowind GOTY on my 2011 MacBook Air (Intel HD 3000, 4gb ram) using the Wine wrapper by HiPhish. I've managed to install it and everything seems to be working fine except for a strange and very annoying graphical glitch. Everything seems to look fine (I haven't explored very extensively yet, only to Balmora and surrounds) except for two things: Firstly, the bodies of all characters, including NPCs and my character, are mangled. The bodies look a little as if they are inside out. The heads and legs appear normal but the torsos are partly invisible and partly rendered in randomly shaped planes of flat colour (no texture). Secondly, the hanging sign/decoration type things found on some houses in Balmora and elsewhere appear normal, geometry-wise, but have no texture. I'm guessing that this has something to do with my graphics card, but I have no idea what, or if there is anything I can do. The effect is so jarring that it makes the game pretty unplayable since it really kills the immersion. 

Any ideas?