I had it going for a couple of days there since my last post, but now it's gone again, for no apparent reason. Along with another forum I frequent.
I got my mate to check when he was round here the other day with his flash laptop, and he can definitely load the page at his house but not at mine when he's using my connection.
My guess is that something dodgy has happened to one of the big DNS servers that these ISP providers all use