Ok, this sounds a little familiar. There have been two people who were able to get this solved using a trick using RUU, as reported in this post at xda-deveopers: xda-developers - View Single Post - [Q] semi-Bricked?? fix?
(And here is the full thread: [Q] semi-Bricked?? fix? - xda-developers
This thread is a little less geeky and will hopefully walk you through everything you may need to do to recover the phone: [SOLVED] Anyway to Unbricked a Droid Eris? - xda-developers
By the way, just to ask, how did you root the phone? Did the root method install clockwork recovery or Amon_RA?