laughingperson, thanks. I didn't see your reply before I submitted my edits.
So even though I am not authorized to use that 1.3 file, iTunes will still sync it over to my iPhone and let me use it, but only if I delete the latest version off the iPhone?
It looks like I can't even sync over an authorized version 2.1 of the app, without deleting the version 2.2 off my iPhone first. Not sure I want to delete the data though, so I'll have to think about this.
EDIT: looks like my other thread got deleted, so just wanted to clarify to anyone who missed that thread - I am NOT trying to engage in piracy. I bought the app, and then later upgraded it. But I made the mistake of upgrading thru the iPhone instead of iTunes, so the old ipa file was never saved on my computer. I liked the old version better, so that's why I downloaded the ipa file for the old version off a web site, but it looks like I can't use it without deleting my data.