I work in the lumber department of home depot and use the panel saw everyday. There is a sign up that say "no precision cuts" and there is a reason for that. That saw is not designed to make accurate cuts its designed to cut plywood in half so customers can take it home. In fact my department head has actually told me numerous times that if a customer wants something closer then a quarter of an inch, take them to look at some table saws.
The saw has a bad habit of cutting slanted too. I spoke to the guy who services the saw about it, and he said it is to do with the rollers the saw is guided by. Usually it ranges between 1/16-1/8 of an inch difference between the top and the bottom.
However if you are EXTREMELY care full you can get some pretty good cuts out of it. It takes a lot of time and practice though. In fact just tonight I cut down 2 sheets of MDF to make a 4th order for my self using that saw, and got it pretty **** accurate. It took me an hour and a half though, and most employees aren't skilled enough or simply don't care enough to take that much time to cut your wood. Also 90% of the other Lumber associates don't consider the amount the blade takes off when you cut, and you can lose 1/8 inch on that.