Unable to Verify message

I have just restored my powerbook to OSX version 10.0.3 (I did not want to, but this was the only boot disc I have). Anyway, I am trying to re-install some of the software I have and whenever I try to mount a .dmg, a disk copy box pops up and gives my Image Name, Image Format, and Checksum, and the message "Unable of verify". How can I fix this?!?

You can get the .dmg to mount by clicking on the "skip" button, but you still have the checksum problem. When you install you may still have problems.

After you did the restore, did you verify permissions? If not try that first.