CM Updater and CWM issues

Hello,
I have already asked this in the CM10 SGS3 discussion but could not get any help there, so I assumed this will get more attention.
Recently, I tried updating CM10 using CM Updater but CWM failed to update, complaining about signature verification of the update package. The full error was: E:signature verification failed.
Has anyone encountered this error before? If so, how can I fix this? And also - could have been any harm done due to failing signature verification on CWM?

Thanks!