gerber decimal settings trailing vs. leading zeros and 4 or 5 decimal places.  Just a guess.  Without knowing the exact conditions its hard to tell. but look into the settings first.

Lum Wee Mei wrote:

I have a question regarding Gerber output. Most of our designs are done with 6/6 (trace/spacing). One one occassion, our regular PCB vendor called us up and inform us that they found some 5/5 on a particular layout. However, when we call up the layout on our workstation with grid at 1mil setting, we found that the so-called problem area to be a perfect 6/6.

Recently, this problem cropped up again with another new PCB vendor. Once again, our layout show a perfect 6/6.

Can anyone throw me a light on what could be the problem. My Mentor Graphics rep mentioned that it could due to the CAM system used by our PCB vendor.

Thanking in advance.
Regards.