I used the environment as discussed above:
Mac OS X 10.6.6
I was not able to move forward cleanly with STS. A couple of "gotcha's" that folks should be aware of. Given that you may have a working directory like:
you will want to perform some house cleaning when changing versions of STS, ROO or any of the other items. I realized I forgot to cleanup the cache and sts-cache directories when starting from scratch. Also, if you happened to change your STS versions, you will want to delete the .eclipse_keyring file found in your home directory.
I'll give the STS rebuild another try on another machine later this evening.
Fight the good Fight!