After repeated failures to install OTA, I finally broke down and created a .alx file manually and installed via desktop manager.
I'll paste it's contents when i can, however it's a fairly basic xml file that just references the .cod file listed in the .JAD file from the demo servers..
Not sure why the .jad file on demo2.zimbra.com isn't working on my Curve, but it isn't.
Perhaps it's a syntax thing, extra whitespace, incorrect line break - who knows.. didn't dig far enough yet.
Needless to say - after all that I have ZimbraME installed and it's working great.
Now if it could only sync my calendar/contacts to my actual bb calendar/contacts apps instead of running inside of itself I will be a happy guy.