can't use libelium gprs with arduino mega

hello friends,

i'm at my first arduino project and having fun with my new mega and a few sensors.
however, the other part of the project, the gprs module from libelium, refuses to show life of any kind, and i feel frustrated with waiting for their customer support.
have you experienced any problems with libelium gprs on mega, or better yet, have you solved them?

thanks in advance,
alex