I am seeing a similar issue. I upgraded to 9.1.507 yesterday, and the system has been very slow. I found this thread, and after reading it, noticed that ZA is doing the same think on my HP laptop (Win XP SP2). CONSTANT disk access by ZA. Are others seeing this problem as well? Looks like I might have to downgrade as well to get my performance back up. Is ZA support aware of this issue?