Are the eye textures in the same location as the rest of the textures? What are your settings in the Advanced tab of Render>Render settings? Does it still crash if you remove the textures from the eyes? How about if you do a spot render? The problem is that Vista is new and so not many people have it, and those who do don't yet know the catches and work-arounds. As an XP user all I can do is try to spot things that might provoke a different response from the OS.

If you've never had a reply from Tech Support it sounds as if you may be falling victim to the a spam filter - possibly on your system but more likely, if you check your spam folder, at the ISP level.