Posted: Fri Aug 20, 2010 4:09 pm Re: floating upside down?
A healthy turtle should be able to flip himself over, assuming there's enough water in the tank (bare minimum is a level roughly at least the length of the shell). A turtle that's weak (from illness, for example) may give up after a few unsuccessful attemps at righting himself or may not even try.
Your turtle was lucky that you walked into the room when you did. (I once cared for a disable RES who could not right himself if he flipped over, and finding him that way was a constant source of worry.)
I would keep an eye on that "slight lethargy" just in case it's the beginning of other symptoms (and keep an eye out for other unusual behavior as well). About the lessening of the "freaking out" behavior, it could just be his getting more used to people (the behavior never totally goes away, however).
What is the water temp and basking area temp? What kind of basking area does your RES use?
"You become responsible, forever, for what you have tamed." -Antoine de Saint Exupery-