If I use loadScreenData with anti-Aliasing turned on in the program's startup like this:

ofAppiPhoneWindow * iOSWindow = new ofAppiPhoneWindow();
iOSWindow->enableAntiAliasing(4);

then the texture will load in nothing but solid black. If I bypass this anti-aliasing, it works fine. I also cannot properly populate a texture using loadScreenData in a landscape orientation. Changing to Portrait orientation in the update loop, and then back to landscape after the grab fixes it.