DON'T pull the strips backward at all....that will break something. RCBS's warning is not to be ignored. They will replace the parts you break free...however.
Hope by "drawing back" you have broke something.
The first suggestion is to make sure all the primers in the strips are flush with the strip edge. lays several strips together on a flat surface (anvil side up) and slide (or roll) something with a flat surface across the strips to push any primers flush that are sticking up. I use a wall paper roller, but the edge of a ruler works just as well.
The next thing is to be aware that moving the press handle toward the bench lifts a primer. Even a little moves a primer so it can catch and jam. If that happens just push the primer back down with an allen wrench, dowel, .223 bullet, whatever.
That's usually the only learning curve for the APS system. Once you learn the curve, you won't want to go back to tubes.
I made two simple mods to take the primers off line and prevent the press handle from moving into priming mode when you don't want. Takes a couple of hours and a trip to Ace/Home Depot. Here's the Link
The Pro 2000 is simpler by far than any other progressive....synching problems just don't happen once it's set up the first time. So if it came to you loose, and you have synching problems, email RCBS and get the guages to set it up right. Pay attention to the primer cup centering in the hole in the shell plate...especially small primers. If they don't center you may have to get RCBS to send you another shell plate base. There have been 2 instances of that in the last 4 years that I know about. Rare, but it happens.
Any other problems?...holler.
P.S. I've found that preloaded strips from CCI don't have "non-flush" primers. (at least what I seen) I notice that they are pushed in further than the strip loader pushes them. RCBS could easily put dimples on the plastic part that presses the primers in, and do the same thing.
In that light, I found that if I rub a glass marble over the holes it recesses them too. That has inspired a future project.... making a simple gizmo with a spring and a marble where I can push strips through one after another. Maybe even mounted to the end of the strip loader. Anyway I digress. That's a non problem with preloaded strips, or freshly "rolled" strips.