The consensus on the forums is that you should use the Airport Extreme (AE) rather than the Homehub 3. The AE seems to be superior for both Wireless strength and having less issues with Apple equipment. (well it is an Apple product 😉 It works brilliantly with Inifinty (WAN port is plugged into the White Openreach VDSL modem):
If you don't believe me, please do a search for Infinity Airport Extreme and click the search button!
Hope this helps,
Just to add to Tommy's reply - Don't forget when you're setting up your username and password details for the PPPoE connection on the AE, you can't leave the password field blank.
I hope this info helps. 😄
Had an AE on Infinity for nearly ten months after much hassle with HHx routers.
The AE has not even hesitated in that time and the wifi signal beats the HH3 by a mile.