We've figured out the Vista border issue (we think). We couldn't reproduce it here, but Jim Slater noted that it happens for him when he changes the bordertype in the init. As Calvin mentioned in these blog entries:

Windows Vista Aero BorderStyle Paint problem as non Administrator

Fix your forms to paint borders correctly under Vista Aero

Vista doesn't allow you to change the border type after the window is created unless you are running as administrator (in fact, he duplicates this in C++). He discusses ways around this - but this is not an SP2 issue - there's nothing we can do about this in our SP.