Not sure of Orbit as I do not own one.
But all the WinMo device I have are behaving the way you describe in TD2.
There is apps inside or 3rd party which you can just switch the display off (not the power off), So the device is not off but the display off can save you a lot of battery.
iPAQ H2200 (fr Jun04)
Aku1.0/2.0, 2.50.00WWE/1.15.00/1.30.230WWE (A2DP, Apps in ER), HelmiAKU3.5v1.3
Dopod D810 (bought for my other half fr Jun07, now my son)
O2 XDA Flame (fr Jul07, lousy O2/MWG/Arima WM5, cooked good WM6.5WWE Cotulla2)/SE M600i (fr Oct07)
Nokia HS-12W (fr Oct06~Dec07), SE HBH-DS980 (fr Dec07)
HTC Touch HD (bought for my other half fr Jun09)
Samsung Galaxy S i9000 (fr Jun10)