The wireless connection can be affected locally by numerous eletrical items, if your hub was moved nearer to such an item or you have placed an item near to the hub that could be it.
if not:
Try resetting your home hub, remove all power for 30 minutes, unplug from computer/s if hard wired and switch off wireless at your laptop or switch computers off, switch on the hub - wait until all indicators on the hub have stabilised, then restart your computers and enable the wireless on them.
If you have no fault on your hub that will cure your problem.
bt engineer, May 2009