Panel View Plus screen not updating

[rta53]

A few months ago I was at customer's site and was looking at the PV+ 1000 we had installed for their water treatment system and noticed that I was seeing pressures and flows even though the pumps were off for that part of the system. I had a momentary panic, but when I switched to another screen and then back everything was reading zero as it should have been. I didn't think any more about it until recently when one of our service guys told me about being at another customer, who also has a PV+ 1000, and noticed that the numbers on the screen were frozen or at least not changing. He said he changed screens and when he went back to the original screen the values were updating properly. Has anyone else had this issue and is there a fix for it?