"the document could not be saved. out of memory"

I have a user running Adobe Acrobat Pro 9. Every time they try and save a PDF document they receive the following error: "The document could not be saved. Out of memory"

The user has 8GB of RAM and plenty of Hard disk space. We shut down all other programs, cleared the temp folder, changed the Virtual Memory allocations and rebooted the computer but the problem persists.

Any Ideas?

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