Lighting issues

[Prophecies]

Hey,
So I am having some lighting issues in UDK. Below is a picture of what's going on. However, this only happened after I got the meshes lighmapped. Never had this problem earlier. Anyone know what's going on?

http://img823.imageshack.us/img823/7339/lightingissue.jpg (http://img823.imageshack.us/i/lightingissue.jpg/)


*edit*
Just noticed I wasn't in the UDK section. Sorry about that...

Edit2; Figured out it was lightmap related. If I use small or no lightmaps there are no issues here. But as soon as I have a someone higher rez lightmap, problems start arising. Would it be because I have so many meshes and they sort of cast shadows on each other?

However, this brings up another problem. For some reason my scene is unnaturally dark, and it wasn't so before I brought the new floor in. Here is my current result:
http://img23.imageshack.us/img23/2951/65740560.jpg (http://img23.imageshack.us/i/65740560.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

And here is the result I had earlier:
http://img838.imageshack.us/img838/4436/udk5.jpg

No lights were changed, nothing....

EDIT3. I just found out that it is computer related? I was working at school when it was dark. I bring it home and everything is fine. What could be causing this? It's driving me nuts!

[Mark Dygert]

Looks like crappy ass video card with out of date drivers vs better card?

[Prophecies]

Really? That would be the only thing doing this? It almost looks like it's not taking lightmass into account, despite lightmass being checked when I bake.

[commander_keen]

well the floor lighting thing is probably because of low res lightmaps and/or bad lightmap uvs. If the lightmaps are low enough you might not notice the artifacts, but once you get some more pixels they start to show up. Check the lightmap uvs on the floor mesh. Also do you really need to lightmap the floor? It looks like it would be fine with vertex lighting.