Fujitsu fi-4340 Scanner reports false paper jam (by 6 users)

We are using the document feeder to scan documents but a good majority of the time we get a warning that there is a paper jam. But the scanner never grabbed any paper and there is nothing stuck in the scanner. I opened it up and cleaned all of the rollers thinking it was just not picking it up but that did not help. I am thinking there could be a problem with one of the sensors, any ideas?