The reason they don't work Gav is that manx telecom don't have a deal sorted with the UK companies meaning you cannot text to these promotional text numbers.
Like always the isle of man drags its heel due to a monopoly situation.
Instead of raving anout 3.5G why don't they sort out a few of these problems first, also they need to drop the ADSL by £20 a month the ripping b@stards