I'm using awstats with plesk for long time.. when I upgraded my plesk installation to 7.5.6 I've some problem with statistics.
I've about 40 domains hosted but I've problem with high traffic domains only (i don't know why). Awstats stop to work when iis change logs (every day..). I notice that when iis create new logs (at the end of the day) it create log with same "creation date" of last log and i think awstats don't understand that it's a new log to analyze! (my supposion).
Do you have same problems? Have you some advice?

Well i wanted to change to AW stats too. On the plesk forums where you could try to post your questions i have read on the past suggestions about adding Aw to plesk instead of the curring stats. The problem i see is, there is a reason why plesk uses the stats they use and dont use Aw Stats. Its server load. The current Stats that come with plesk are made for thousands of process per second without server heavy use, so its made for for heavy use. If you have 1 or 2 domains its fine with AW, but i wonder how much Ram and CPU you will use for a couple hundred domains on Plesk each one with AW. So i personally just stick with the things that come with Plesk.