You need to give more information than what you have if you want help.
How often does it happen?
Does it happen while you are in a zone an extended time, or when you change zones?
Have you checked to make certain all your firewalls are deactivtaed (or at least ported for EQ). What version windows are you running?
Are you using EQplaynice? (It doesn't work with win7, btw.)
Anything and everything associated with your connection would be good info to help diagnose this.