DROP TRIGGER IF EXISTS throws error??

[Jesse]

I'm attempting to restore a couple of backups, and part way through, I get 
the error:
You have an error in your SQL syntax; check the manual that corresponds to 
your MySQL server version for the right syntax to use near 'IF EXISTS 
alumni' at line 1

Query is: DROP TRIGGER IF EXISTS `alumni`;

Seems perfectly valid to me.  If I remove the "IF EXISTS" part, then I get 
the error, "trigger doesn't exist".  What's going on? This usually works 
fine.

I'm running version 5.0.45-community-nt

Thanks,
Jesse