Okay, I am going to make a couple of assumptions here because if I read you right I think I understand what you are asking.
First you are using ClockworkMod Recovery and you are trying to restore a backup and during the process the backup aborts and you get an error message then you are back at the CWM (green) menu.
First thing, I have noticed that CWM 2.5.0.1 seems a bit finicky. (I am sure you are aware of how to navigate in the CWM recovery menu, but in case you don't here is a refresher........ Your volume keys allows you to navigate up and down through the menu, you camera key makes the selection you have highlighted, your power key takes you back a menu. ) So while you are in the recovery use your power key until you see the top option of "reboot phone now" then hit your camera key. Allow your phone to boot up then go into ROM Manager, scoll to the bottom where it says you can Flash Older ClockworkMod Recoverys (its at the very bottom), click on that and choose 2.0.1.3. Flash this a couple of times consecutively. Then reboot into recovery and try to install your backup again. This should allow you to do so. If not, let us know and we can try a couple of other things.