I think your thermostat needs to be replaced. They commonly go on these cars and are easy/cheap to replace. Your thermostat may be located in a bit different position, just follow the top radiator hose to the engine and where that hose connects is your t stat housing. Pull this off and replace your T stat and you are good to go! Its usually 2 10mm bolts that hold the housing on. If you disconnect the t stat ground wire be sure to hook it back up. It can really mess with how the car runs if it isn't connected properly.

A sure fire way to know the t stat is stuck and causing your car to overheat is to feel the top hose when the car is hot. The top hose will be hot (car is about to overheat) and bottom will still be cold. Coolant isn't cycling cause the t stat is stuck closed. This method has worked for me every time on Hondas.

Don't waste your time flushing your system at this point. Try this and see if it works.

Youtube vid-

http://www.youtube.com/watch?v=xNAW3NoWRaw

If this works, feel free to donate : )

One more thing, these V6s legends are known to have headgasket issues so... That could be the problem as well...