The Underscore Archives

I used to be able to "sudo -s anyoldcommand" on a remote machine that  
someone else has set up, but now I get this error message when I try  
to sudo:

"mv: mv: cannot execute binary file"

But it works if I just type in the command as a regular user. Anyone  
any ideas? Hopefully the sysadmin will fix it this eve, I'm just  
curious ;)

cheers, Jake