bri, I wasn't able to simulate this problem again (Win7 + IE8/FF). The previous bug was caused by invalid NTFS streams filename parsing so I'm quite surprised you still have this problem... Do you get the same popup error as you mentioned in the first posts?
To simulate the problem, I tried: - create some favs (in IE8/FF), run sandboxed IE8/FF, open those favs, open them in new tabs, create new favs; all worked ok, they haven't been corrupted; should be these tests enough to notice the problem? I'll try that tomorrow with Vista32.