Long load times for GWX are normal. Mine takes anywhere from 3-5 minutes for the game to load; the museum seems to take much longer. Try not to save your game in periods of rain & fog. From what I've read here, saving a game during these bad weather conditions seems to to reset the weather "clock" so you end up with extended periods of crappy weather.
P.S. This page:
http://silent-hunter-addict.com/Ques...m_Members.html can answer many questions regarding SH III (including CTD's). It may save you some time & frustration...