I believe this is a windows 7 compatibility problem with the twain drivers provided by hp. it is important to for precisionscan pro to work properly because it is used by paperport and provides much functionality that is not available from the paperport native scanning application.. If you examine your windowssystem32twain_32 directory, you should see subfolders under there that have the twain drivers installed. one of them should be "hp scan extended", and the twain driver, data source manager, and other stuff is in there.. After 6+ hours of troubleshooting with hp they have determined that the issue has to do with windows 7 moving the twain drivers for both printers into the same folder creating this conflict this was never an issue on other os like xp or vista..
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