Thanks, but i don't think its a graphics card issue. It works normally after the editor is restarted which suggests a editor issue to me.
I guess they're ignoring this thread because i haven't posted it in the bug forum, but i'm not signing upto yet another website.
I can't give any more info than what i've already said here and i've taken the time to bring it to their attention so hopefully they'll want to look into it.