Please keep working with PSG. If the ticket has been closed, please email them and re-open it asap.
(The forums are more for brain storming than trouble shooting, PSG is way better set up for that sort of thing than the rest of us).
All that said, the only thing I can think of off the top of my head is that there must be something rather unique about your setup.
We have a LOT of customers running PAC Display and none of them have this issue.... so to try and drill down and find the combo that is causing the issue is going to be......ah... fun, to say the least.
Are you using the URL window to view a video stream (IP camera or other) or web site?
Got any trends or data logging happening?
They are the two things that spring to my mind when looking for something that slowly gets bigger and bigger.
From your first screen shot, I see around 20% CPU, but it does not drop when pac display shuts down... Whats chewing up the CPU like that? Again, I'm thinking combinations of things that might be causing issues....