Yes, I see the same problem with my paragraph designer. I'm FM9 fully patched, on a brand new Dell Workstation running Win7 Pro SP1 32-bit with 4GB Memory, Xeon 2.53 GHz processor, graphics card is a NVIDIA Quadro 4000 (2 GB).
After awhile, my paragraph designer will simply stop working. I have to exit and restart FM9, then all is well, for awhile. I assume it is a FM9 bug, but I've not bothered to bang my head against the wall with Adobe to see if there is a fix. It's mildly annoying and I've learned to live with it. Richard