Temporary fix I found a temporary fix: Take your screenshot in landscape. Use the free app called "PhotoPad" to rotate it. Then it ends up back in your photo app in the orientation that you want.
PhotoPad fix This fix works perfectly and is permanent if you delete the original. I create paintings with the Brush app and it does not always save the orientation desired, PhotoPad is the answer, thank you!
The only problem is that the saved image has way more compression than the original... Is there any other app that saves better versions ? EDIT: I found that the App "Rotate and Crop" uses way less compression, leaving the picture quality intact.
I am experiencing this same issue (screenshot taken in landscape mode is saved as portrait, forcing you to have to get an app and rotate it 90 degrees for it to be saved correctly. (the app I'm using is eHarmony... I use Filterstorm to rotate and save a new copy... A pain in the a** because of the steps required.). I'll go and report this issue as well. (iPad2)
the printscreen issue also happens with my ipad2 3g for cropping and rotating, i use CROP SUEY HD... so easy to use...