Now that I know what my problem has been all along I made a few tests. Rebooted my PC. When my Vista was loaded (no HD activity) I started PoserPro to see how fast it was to start compared to P8. PoserPro took 1 minut and 14 sec. to start until there was no CPU/HDD activity and ready for action. I had 6.3GB of ram free (I have 8GB installed).
Now it was P8s turn. Same steps as above. It took P8 3minutes and 38 sec. to start up!! The search was the bad guy here as I could see on the folder numbers when the search was over. No wonder I sometimes couldn't find anything in the folders :-) But after it was loaded I had only 4.4GB of ram left. Can this be the search thing that does that or is it the new P8 engine that eat up all my ram?  Almost 2GB more than PoserPro! My CPU was also using 25% of a 4core CPU even though P8 was finishing to load and was idle. If I minimized P8 or closed the preview windows the CPU load dropped to 0%.