Xr650R - 2000-2006 are water cooled.
Check this site out. www.xr650r.us
I have been on the yahoo forum that the above rider moderates. Unfortunately I only have 2600 miles on mine, so I can't tell you much from experience.
One guy on the site overheated his bike, kinda like you said and had the guides come loose, which would cause some more issues that you might want to check.
According to the posters on the yahoo forum, overheating is inevitable if you are going at a walking pace for 10 miles. From what they say this is especially true if you have "uncorked" the bike.
The thermostat is a common problem.
Some of the desert and hard core trail users put Evans coolant in their bikes. It is a pure glycol mixture and boils at about 365 degrees. Thus it stays unpressurized and in you radiator at higher temps. I personally haven't tried it, and am avoiding it if I can, as my riding is much easier paced then theirs.
Anyway, that is what I am hearing. Personally, the bike is a purpose built dirt bike, and may require more TLC than some other DP bikes. Recomended oil change intervals are 600 miles :o
David
