element.style.border = "" fails to cause style-recalc See example.
Created attachment 9461 [details] example demonstrating failed style recalc
This is definitely a dup, but maybe not in bugzilla yet. (Easy workaround is to clear the actual properties rather than the shorthand).
This is actually one of our more prominent CSS bugs (it has been mentioned on numerous Web sites and blogs). I'm going to add the CSS1 keyword to this and up its priority.
*** This bug has been marked as a duplicate of 9284 ***