When I enter Single-Player mode and I want to use a slash command it crashes.  I can't even do /count.

Is this how it is supposed to work?

If not, what do I need to do to repair it?

I'm using WoMClient-1.6.6 on a Vista Toshiba Qosmio X305 Laptop with Service Pack 2, 32 bit, Intel® Core™2 Duo CPU P7350, 2 GHz with 4 GB memory.

Thanks in Advance,
Le Joueur