Thanks for the replies, the housing management are sending someone out in but haven't got a date yet. Would a faulty lnb also cause the problems i'm having? When i got he box back in January it was never perfect but used to pick up more channels than it does now from the xml file and would populate a bouquet from ABM. I just used to manually add the missing channels using the frequencies for the channels that I'd found using blind scan in the weteks own software. But this is impractical now.
Also I plugged the receiver after scanning at my parents it would display 0% snr for a lot of channels. Most channels it picks up now are the sky HD channels which are obviously no use.