Login into the router and have a look at the settings. From your PC (which I assume is connected by a network cable to the voyager) you need to type in something like 192.168.255.1 (the BThomehub has an address something like this iirc). Have a look at teh wireless settings to verify the ones your typing are correct.
Maybe try turning off the wireless security and test it that way.
Have you tried resetting the router to factory settings?