You should update to SP2
as that will fix allot of other Vista compatibility issues.
DDS is a Direct X Shader texture format. If you don't use DDS textures, don't worry about it. If you do, here
you can dl and reinstall the dds plugin. That might fix the bug.
For the viewport issue, try checking the 'Disable Desktop Composition' box in the Compatibility tab.
If that doesn't work, try switching off Aero.