Was still thinking about your connection issues after you left last night. You said you were using the FiOS router. It would be reasonable to guess that you have at least one neighbor doing the same.
Both routers would likely be configured (by default) to use the same wireless frequency channel. Interference between the two could create the connectivity issues you describe.
Consider running through this guide to figure out if this applies to you:
The fix may be as simple as changing the wireless channel configured on the router.