If you are running PokerAce Hud and you aren't getting stats, then the first thing you should do is read through the tutorial. The tutorial covers the configuration of each poker site and gives you tips on how to use PA Hud with each site.
http://www.pokertracker3.com/products/PAH/docs/
If you are sure everything is configured correctly and you still aren't getting stats, check the following:
1. Make sure you are importing successfully into PokerTracker.
2. Try turning off any filters you may have set.
3. Make sure the correct databases are being used.
4. Make sure the players have enough hands to meet the minimum required.
If you've checked all of the above and are still having problems, then make a post with the specifics of your problem. Please mention that you have read through the tutorial and checked the common problems and nothing has helped.