Yes... I've had the problem too, but each time it was because I had went thru a deep mud hole and plugged up the radiator... haven't come up with a solution other than staying out of the really deep mud holes ;-) .
I ride in mud all the time and I have never had mine overheat. You may have a faulty waterpump seal. Mine was leaking and at first I thought that the water was coming from the overflow but it turned out to bethe seal drain that lets you know that the seal is bad. It is just inside the frame rail by your right foot.
Well, the bike is now back at the shop once again regarding it overheating and losing rad fluid out the weeping hose. I went outfor a ride last Sunday with the boys and I noticed that when I started the bike up first thing in the morning while butting on my gear I say a small amount of rad fluid comming out the hose. The bike was in the shop to get the valves adjusted and a oil change so I thought that they might have checked or added fluid during the service and didn't think to much about it. I brought along some extra rad fluid just incase. We put on 103km that day and the bike overheated 4 times and I had to top up the overflow bottle twice. I brought it to the dealer on Monday and I get a call Tuesday saying the the water pump is now junk thanks to the inner seal. To top it off, it's also on back order up here in Canada as well as the US. This is the second major problem with bike with only 600km on it. At 75km the tranny O-Rings blew and I had lost 3rd gear and it took 3 weeks to figure that problem. I called the Honda Customer Service number and all they could do for my time lost ( 1 month at the shop ) is to put the water pump on Emergency Order. "YA what ever lady"!!. Will keep you posted on the outcome of this mess of a bike that I seem to have bought for $12000.00