Document feeder doesn't recognize that paper was fed

I’ve got a year-old HP OfficeJet 6958 where the ADF will feed pages but the printer doesn’t recognize that a page has been fed.

This occurs for both the Scan and Copy functions. The pages are picked-up fine by the ADF, passed over the scanner and sent out to the exit. After all the pages exit the printer I get this error from the HP OfficeJet 6950 software:

A scanner Document Feeder misfeed occurred. Clear the misfeed, reload the page(s), and try scanning again.

And this error is displayed on the printer:

Reload Original

The document feeder was not able to pick up the original. Make sure the document feeder cover is closed completely, load the originals in the document feeder, and try again.

I have carefully inspected the ADF and ensured that it is fully closed. I have tried the disconnect the power cord, wait 60 seconds , plug it back in and wait for the printer to initialize but have the same problem.

The printer is running the latest firmware ( 040.007.1094.16327) from HP and I’m using version 20.78.0.5774 of the printer driver. The printer is connected via USB. However I doubt this is a driver or USB problem as the printer shows this error ever when not connected to any computer and just using the Copy function.

Anyone got any ideas on how to fix this?