Protect seems to only have a 2.4Ghz radio, at least that's my experience with my house full of second gen Protects. That wifi spectrum can be impacted by metal objects (refridgerator, etc.), bluetooth devices, microwaves, cordless phones, and of course neighbors if you're in a townhouse/apt/condo who have any of the above plus their own wifi. Too much overlap between access point signals if you have more than one, especially if they're on the same channel or have their transmit power set too high (which many people are inclined to do for maximum range), can cause this as well, as can neighbors who create such an issue.
If you're in a single family home, then it's probably not the neighbor issue, but perhaps you have more than one access point. If that's the case, you may be able to tweak the channels they use, to prevent them from overlapping, alter the transmit power, or move them further apart if it's a congestion issue.
