First off, this program is sick! I'm so happy to have finally found a id3 tagger that works well enough to motivate me to fix up my mp3s. Thanks.
Ok, step 1, type this into the format string field on an arbitrary file:
$replace("test", "e", "e")
That works fine, shows that output file being called "test.mp3". Everything is good so far, right?
Change the first "e" to "", so it will look like
$replace("test", "", "e")....whoops there it goes.
My guess is there are other similar bugs but repeatedly crashing the app isn't my #1 idea of fun. =)