Have Been INTENSLY using P5 since yesterday and even doing the unthinkable [opening manual] and have had no problems. In case this helps - am running XP Pro with all updates, 1.8g and 512mem with over 11g harddrive free (even after install and leaving P4 on). I do continuously defrag my disk. Everything has been doing fine (hair, face, clothing, material rooms and bringing in P4 stuff) except rendering, does leave alot to be desired (dead slow) but havent reached that part of the manual to tweak it. I virus scanned, defragged and closed all none essential programs before installing and installation and registration went without a hitch. I think you shouldn't cancel the order since you can still use both P4 and P5. DAZ's freebies are even smart enough to find both poser.exe files and lets you install to whichever one you are using. I am happy with new play toy!