Is the GFI in the basement on a dedicated line? If not you might have plugged something in another outlet that's using the same GFI. In many instances, additional outlets can be wired through a single GFI. Typically you find that in Bathrooms and Kitchens.
You can also have a bad power cord. Somehow the insulation might have gotten damaged and allowed moisture into the cord. Rodents love chewing insulation. Check the cord and check the TT too, no telling where it might pop up.
If you need to replace the actual GFI, make sure to get a brand name one! Places like K-Mart, Wal*Mart and such, sell Chinese Crap.
Have a good one,
Hey! How's that "HOPE & CHANGE" working out for you?
January 20, 2013 - The end of an ERROR!