Water dispenser problem

Dispenser can fill gallons if I had to non stop. Once I stop, if I wait for more than 10 seconds, it will stop working. I have to keep trying for almost an hour then it might work. Sometimes I wait days & try again, then water will flow. I hear the "hum" sound from the back when it’s trying to dispense water. No water. Ice maker is working fine. When I take the line apart from the in line filter, there is good pressure. Fridge has been working fine up until now. My warranty from Circuit City ran out in August (I forgot to renew!:eek:) Any suggestions?:confused: