How to get the correct revision number of Cosmos :

Open the Cosmos.txt file (it should be located in the WoW directory)

Check the second line in the file. It should look something like this :
r873 | drisse | 2004-08-06 23:59:03 -0500 (Fri, 06 Aug 2004) | 1 line

The numbers after the "r" (in this case, 873) is the revision number.

It is EXTREMELY helpful if you mention what revision number of Cosmos 
that you have, since that makes it much easier for us to see if it is 
a bug that have already been fixed.