Default radio upgrade?

hi guys, im in the u.k and owened this phone for over a year..
just wondering if there are any radio upgrades available for this phone as the reception is seriously poor, now im not sure if i was just unlucky in getting a bad handset, or if its to do with the frequencys used in the u.s & u.k. (i checked before i got the phone and the frequencys should be the same)
when im in the house i put my sim card in my old htc desire z & turn on wifi hotspot and use my glide using wifi.

so, i was just wondering if there were any tricks i can do to improve reception such as flashing a diffrent radio version?
thanks people..