Jake Gilleland, Home Inspector from the Dayton area, writes this excellent post about GFCIs (Ground Fault Circuit Interruptor). Now you may know why one may trip, but the problem is elsewhere:
What are the things that you don't know about your home? They are all the important things that you don't know are important until you need to know them. Now is that clear to everyone.
Normally, if you have lived in you home for a while you know how to reset your GFCI (s). But if it is a new home or it has just been remodeled then you may not.
Did you know that you can string two or more GFCI's together? This means that if something happens at one outlet the reset would have to be pushed in another location. I'm going to use a real house as an example here. There are 2 upstairs (2 full baths) GFCI's and 3 downstairs (1 half bath and 2 in the kitchen), but they aren't all GFCI type outlets. Some of them look like normal outlets, but they are wired together. The secondary outlet (the one that looks normal) will be wired to the one that looks like a normal GFCI.
Some personal care products are well known for tripping GFCI's especially the older style. So the first day it happened as one of the kids were getting ready for school
it was difficult to find which one had actually tripped (due mainly to the time limit imposed by a teenage girl standing in the bathroom with dripping wet hair and only a half hour to get ready).
If you have a GFCI in one bath and none in another then it is likely that the bath without one is connected to the other. Check the reset button on the primary if the secondary outlet is no longer powered and that should be the correction to your problem.
For more information visit http://www.cpsc.gov/cpscpub/pubs/99.html.
Now, maybe you did know all that and if that is the case I apologize for repeating it. If you didn't then you now know something about your house you didn't know before.