We found a partial answer.
You can disable pdf/a mode by going into Edit->Preferences->Documents->PDF/A View Mode. Then change "View documents in PDF/A mode" to Never. This significantly reduces the steps to rotate images.
- Open the PDF file
- Rotate the document under Document->Rotate Page.
- Save the file. It will automatically save as a pdf/a file.
I still don't know if there is a way to batch rotate files. This feature might only be available in newer versions. Let me know if batch rotating is possible in Adobe Acrobat Pro version 9
You can use a batch sequence for this.
Use Action Wizard Tool!
Not available in Acrobat 9 Pro.
Bear in mind that any edit to a PDF/A file will stop it being PDF/A. So it is not enough to just find a way to turn off warnings. You do specifically need to save it/preflight it BACK to PDF/A after any edit, no matter how trivial.
You might be able to use preflight to batch remove PDF/A, then make the changes, then batch convert back to PDF/A (three steps). But I'm not especially hopeful in such an old Acrobat.