When logic doesn't cut it

I've learned quite a lot these last two days. But it's still not enough.

The socket on the back patio keeps cutting out, the only proof of this being the fact that the lamp isn't lit. 
Duh!
After some investigation, it turns out that it is a "downstream" socket controlled by a Ground Force Circuit Interrupter (GFCI) socket by the front door. (Pats on back for technical terms)
With supersleuthing skills, we found this out by pressing the bloody reset button, which turned everything back on again.
But only for an hour or two.
Rinse and repeat.
A call to our friendly neighbourhood help guy was somewhat meaningful in that he advised us that since the boss had ran the hose pipe over the back patio yesterday, it could be some water has got in the socket. (The perils of cleanliness eh?)
What to do? Leave everything unplugged until real spring temperatures arrive and see if it's solved, i.e, dried out. 
If not, change the GFCI. 
A simple enough job, it's spending the $70 or $80 to buy a new one that hurts.


Ah well...