Handset 3 not able to make or receive calls?

Hi I have a BT Freestyle 3200 cordless system with 4 cordless phones, all ok except for handset 3. I am unable to call it internally or transfer a call to it, plus when I try and make a call. on pressing the outgoing call button all I receive are beeps and no dial tone. The handset is showing number 3 (handset number) and the receiver aerial is showing in the left of the display and not flashing(I know that if aerial is flashing the handset is out of range). I have removed the batteries and had the handset re register itself but still the same fault. The batteries are fully charged. I have tried the handset next to the base station and still the same issue. All the other handsets work fine.

Any ideas?

Regards

David