Interesting. It's a Mac OS X Tiger machine. I'll have to go back and try again -- it just looked like the path parser was staring blankly at a malformed path.
There is in fact an infinite path loop if you were trying to scan subfolders, as something is presenting a folder with no name, whose children --
according to Explorer -- are the same as the parent, leading to an infinite loop. That might be upsetting your directory structure checker somewhere causing it to bail out and die.
Anyway, I'll check back later and try the old Mac and my laptop.
[
Edit: Sorry -- per the linked page, I'm in OS 9 not X ;-) Forgot.]