you need upload the screenshot - evenhozion needs see it
I don't need a screenshot of that, since I've seen that issue lots of times before. The initial button corruptions aren't related to mipmapping, and have to do with backbuffer rendering corruption - did you by any chance upgrade your video drivers recently? Sometimes newer drivers can cause weirdness, and sometimes they can fix issues. Also try playing around with the r3dopengl.cfg file that I mentioned here:
http://forum.skyscrapersim.com/index.php?topic=661.msg8182#msg8182 (the options I show on there have to do with the text rendering).
As for the fullscreen issue, that happens on quite a bit of cards (mainly seems to be ATI ones), and so if your system has issues with it, then don't press F10

- to try to fix it, you'd have to mess with the options in data/config-plugins/gldrivers.xml (that's used by Crystal Space to disable or enable certain OpenGL features on a per-card or per-driver basis, in order to fix problems).
-eventhorizon