The 27xxp series has been known to be unable to rotate all 4 ways when on battery.
A workaround for this was posted by C-141XLer @ gottabe mobile
http://www.gottabemobile.com/forum/f...?TID=7399&PN=2
Here are the steps I took to get it working
1. Stop igfxpers.exe (Persistence) from starting up on windows load, by unchecking it to start in a startup modifier. I used Glary Utilities but the simple tool Autoruns should do it.
http://technet.microsoft.com/en-us/s.../bb963902.aspx
2. stop the igfxpers.exe process in task manager, this is so you don't have to restart. It should not start again if you did step 1 right.
3. Now you can rotate all 4 directions using the mobility center(search vista apps), Still blocked from using the intel app or button for all rotations.
4. To make it easier to rotate install the app called irotate, this will allow you to change it easily from the system tray.
http://www.entechtaiwan.com/util/irotate.shtm
That does the trick for me, let me know how it works.