I never once installed windowsblinds, I used the uxtheme.dll patch for about a year, then this just suddenly happened.
Right click and go to properties>appearence, and make sure "windows classic style" isn't enabled in the "windows and buttons" section.
Eh, I that won't fix it, I've messed with Appearance so many times, that was the first thing I checked like 3 months ago.
I dunno then, Windows might have reset the uxtheme.dll file after an update or something, or you might not have it at all.