Bryan something has changed. I went through scans I made with the Cezanne and found no evidence of what your finding. There were scans on the cpu I sent, I'd suggest you take a look to confirm. I scanned 8x10 and batches of 4x5 covering the bed without issue. I believe there are no driven cogged wheel/track systems in a scanner like this. The stepper motors just make a step based upon a controller which determines the size and frequency of step. The engineer in me tells me these system either work or do not.

I'm still thinking some sort of intermittent electrical problem. At one point I thought maybe static build up, or scsi cable/connections. A good cleaning can never hurt, I've never had it apart, but I can not see how it can cause such an intermittent problem. But if the glitch happens in the same exact spot, I find that confusing, maybe some debris on the carriage track. Because the bed was locked down, any issue from jolt in transport would likely only occur in the starting position.

I suppose we should not rule out the computer and/or software somehow corrupted the database but this is an area I'm not conversant in. My software background is network and physics for gaming.

bob