Oh - in that case your checking is bugged, because i only create a file containing "ECHO TEST", just think for second about it: MD5 tests the checksum of a file, dont you think a configfile could contain many different values ? And the error-message says: MD5-Mismatch (content checksum NOT the same as it should be).
If you still dont believe me, try it yourself - make a fresh et-install, create a ubot.cfg in etmain and write ANYTHING in it, go to a pb-enabled server and you will get banned.
And why is the list of the forbidden filesname not handed out ? cvars can be checked by players, but not which filesnames are not allowed.
Edit: And yeah i used the name UBot to test it .. was curious if the other admins would do anything about the name. :P