Graphical Glitches and other problems

[Greatgraddage]

Hi all,
I got a copy of SH3 a week ago from amazon (only a tenner in the uk, bargain!) and I'm loving it, the atmosphere has me hooked. I've been having a few small problems though that sometimes occour, not always but now and again. The biggest problem is that intermittently my periscope won't work for an entire session of the game, I can go in the room, raise it but as soon as it its the surface it messes up, major slowdown, I just hit f2 multiple times till I get back to the command room and then just live without it. Attacked my first convoy without it, surfacing, firing a salvo then crash diving. At dusk. How I survived I'll never know. But that's another story.

Also recently there's been numerous small graphical glitches ranging from this:


To the whole crew in the command room dissapearing.

Has anyone experianced anything like this before? I did a search and couldn't find anything. Cheers in advance for any help!