iChat Not Working

[izzy35]

Hey...Is anyone else having a problem with their ichat plugin not
working?? I am on a macbook with leopard and the ichat options come
up, but when i click return, nothing actually happens...is there a way
to fix this?? Also, when i go into "handlers" the instant messaging is
set to ichat, but it is shaded and i cannot make any changes to
it....ANy help is appreciated...