Sorry for the awkwardness of the question. I have some really ridiculous rules (but I like them...) to rename my files, and the script gets really long after only a few rules with a lots of nesting, etc. I wonder when will Mp3Tage broke down and stop handling my script? (I heard somewhere that Microsoft Office VBA cannot handle more than 7 levels of nested if/for/etc.)
There is no known limitation (except your machines' memory).