Most likely cause (other than a local jammer), is that the garage door transmitter is locked up and outputting a mass spectrum of RF noise

(I've seen this in 3 blu-ray players working the other way where their WiFi cards go bad and blast wide spectrum noise knocking out any wireless communication from about 29hz past 6ghz). this is usually for about a 10-15 radius though; and is why its more likely on the garage side as their range is generally greater then wifi

(yes I know this is related to frequency band, but it is still generally more powerful than a wifi signal unless you use a high power or longer range access point).

While not likely, it is possible if the WiFi uses a frequency multiplier scheme. Or, if the WiFi includes a processor that uses a clock frequency in the Door Opener's band.

Do we have any more data on this point?

If this is consistent, try using the WiFi before, then after attempting to use the door transmitter opening the door.

A wild card to consider is the battery condition of the Door Opener transmitter. A sloppy design might develop some quirks as the battery approaches end of life.

Don't know what the actual issue was, so I replaced the router and all is well. I can even open my garage door now. Thanks for all the help and suggestions.

Sorry late to this thread, but if you put LED bulbs in the openers they can sometimes cause issues. I put some Cree ones from HD in my opener and it would work to open the door when we came home, but would not close it leaving. (ie would not work when light was on).

Swapped them out for the Utilitech's from Lowe's and the issue stopped.

Good to know, I do have LED bulbs in the openers.

I was finally reminded of a client who had a PAR lamp in the garden that made an audible buzzing sound. Whenever it was on, TV channel 37, which we used to modulate his satellite receiver's output, went dead.

Wow, I've only seen schematics for non-dimmable bulbs so I thought, what?. But it looks like dimmable are a different story (this had LED and CFL): [Link: electricalpollution.com]