I just stumbled upon this thread and realized that the previous posts have pointed me to a solution to a problem that has been bothering me lately, namely the slow starting of OO.o 2.4, especially Calc. I have followed the above suggestions and have added the component stclient_wrapper.exe to the CMF Exclusion list: the problem has gone away.
I do NOT get the "reinstall product" message in CMF so this is a separate issue, I think.
For the record, this is the seventh item added to my CMF Exclusion list. The others involve DropMyRights, an obscure part of Acronis TrueImage, three Cygwin procedures, and MS dumprep.exe. All signal there need by pinning the CPU at 100%, sometimes for a finite time (the current case), sometimes "forever" (the other six).
Thanks to the previous poster for finding this!