Please, please, anyone using a BT Home hub do yourself a big favour and stop right now. Go out and buy a decent router that BT don't control. I spent some long time earlier this year playing with the hub and everything that I found bothered me (and others with whom I corresponded). The is a crippled Thomson router which is locked to BT's network. They routinely update the software remotely without your agreement. You can lock it down to prevent this, but frankly why bother - just buy a decent router.
I documented this at http://baldric.net/2007/01/22/bt-home-hub-and-the-gpl/. That post also points to comments from me (and many others with similar experiences - see Kai Robinson in particular) on a good site called homehubblog. See for example http://www.homehubblog.com/2006/12/23/christmas-present-from-bt/.
Mick
Ill have a look when I get home, but Ive done exactly the same thing as you and I can access my apache webserver ok. The only slight difference is that I use dydns name instead of IP address but this is the same. Also I had no idea it was possible to access the BT home hub management interface from the internet. That is rather worrying considering how often it resets itself and port forwarding rules disappear,