Remote Assistance not working

[Oz]

Hi There

I am having problem offering remote assistance to my mom's computer. This is
what happen. She sends me invitation, I accept and this is what I see(
Attemting to connectect..).

After 1 munute I get this message { Remote Assitance Connection could not be
established because the remote host name could not be resolved.. Please try
again}. I have traid couple of times with no luck.

I dont have any problem helping my brother.
We all use latest Windows XP.

Please Help me