Electrical problem with GFCI
I was thinking the same as user19141. You can have more than one GFCI on a single branch circuit. But only if they are wired correctly. If we pretend we are electrons traveling down your circuit, It would leave the panel and go to your first GFCI at some point. If than at that first GFCI you leave that box on the load screws on your GFCI and run to a couple more plugs, than another GFCI. It will not work properly. The point being that another GFCI can not be ran off the load side of another GFCI. Perhaps this is the case? And it just started acting up because thats the way it goes sometimes!