my friend had one of these,which he had purchased from argos.Exact same fault as yours,
he returned the box and got a replacement,his replacement was also duff,it started freezing on record.
He said he was going to get his money back and buy another, but a different brand.Haven't spoken to him for a while so don't know if what he bought is ok.
what iam trying to say is this,are the boxes faulty,or is it due to a weak signel ??,
bad weather etc....
Just thought I would mention this,hope you get it sorted.
paul, April 2012