When I log into my PC via GoToMyPc, all the other computers in my house lose connectivity

"It sounds like your router is misbehaving when GoToMyPC is active. This is likely just something screwy with the router firmware, when it detects a certain type of packet incoming it's going haywire and disabling the wireless network.

You can try upgrading the firmware on it -- make sure you get the right version for your device; they list different files for v8.0, v8.1, and v8.2.

If that doesn't fix the problem, you can

try a third-party firmware (DD-WRT, OpenWRT, Tomato) if your device is supported.
try a different router (different model linksys, even a different version WRT54G, may not have the same problem)."

Yes, I also think that GoToMyPC may be affecting. I use pc file transfer. I have several computers set up with this program and it works good. I don't have problems with this remote application tool, ever.