I saw your post in Mikey's condo about the PetSafe 5 compartment feeder. That's the one we used for a long time - probably almost 2 years.
The key to having it be successful is to make sure the food tray is fully seated into the base unit. You put the tray down on the base, then there is a button to press to move the feeder around one rotation. If it goes the whole way and opens fully under the cut-out in the lid, then it's going to rotate ok through the rest of the compartments. If you don't have it down all the way into the base unit, it will only move partway and then it will be impossible for Webster to eat from the compartment. We also set the food tray in the base back one or two compartments so that we could rotate it, see that it worked, and then move on with our day without having to mess more with it. That probably doesn't make sense now, but when you get it, I think it will.
Punkin had a mighty appetite, courtesy of the acromegaly tumor. He couldn't break into the feeder. There's not really anything for the cat to get ahold of to move the tray around.
If you have any trouble with it, say so and I might be able to troubleshoot it with you. I thought it was a really good feeder and I loved having 4 covered compartments to be able to leave many mini-meals ready to go.