[cliffpage]

i obviously dont know the wording of your insurance policy but a household policy would usually cover things that were legally your property and other things that you were responsible for but not technically own outright eg. something you had on hire purchase and items you rented like a TV and something like this cable box.
I can understand that the policy might exclude items belonging to your landlord but i still would have thought it would cover items that your are responsible for like the cable box. If an insurance company is saying the claim for the box is not valid, have they actually shown you the exact bit of the policy that they are relying on when saying this. or are they just fobbing you off too easily.

the bit about the bike above is a red herring. the owners of the house where the bike was stolen from could not have it paid under that policy as they did not own it, NOR was it their responsibility as they had not entered into a contract to rent it / safeguard it and look after it (eg. the vigin cable box contract).
The owner of the bike should have claimed on their own insurance policy - but of course it would only be covered if they had cover for their items away from their home- which usually costs extra