Problem with water shader

Whenever I go underwater, instead of the refractive shader being applied as it should, it’s being applied to the entire screen, including the HUD, and nothing is getting rendered (kinda). The same problem occurs with the insides of Stargates from the stargate addon. The problem stops immediately when I leave the water, but makes it impossible to navigate underwater. Is there a way to change the default shader for use underwater?

Processor: 2GHz Intel Core 2 Duo
RAM: 4GB
Graphics Card: ATI Radeon HD 2400
OS: MacOS 10.6.2 (Running GMod through Crossover Games)

Addons (although this problem occurred before any addons were installed):
Wiremod
UWSVN
Stargate
PHX
SmartSnap

Before entering water:

After entering water:

Pictures?

Oops, sorry. I’ll have pictures up in a few minutes.
EDIT: Pictures added to original post

Any ideas?

Im pretty sure its a bug caused by Mac.

I know that it’s probably a compatibility layer bug, but how can I change the refracting shader to something simpler?

Hurrrrrrrrr