I found the solution... Moving to CPanel
After looking for information in Internet as well as the Parallels manuals and wait for assistance in here, I realize that Plesk is a bad platform because:
1. It has never been possible to upgrade to new releases. Plesk 9 is not fully compatible with 10.
2. There is no forums over the Internet with skilled professionals.
3. The company does not give support to those hosted with their resellers.
4. Those resellers does not have good support from Paralleks, even when it is very expensive.
5. There are extra charges all the time: The antivirus, the antiSpam, shopping cart, etc.
6. Plesk 10 interface does not follow the previous paradigm, neither offers clear benefits nor is well documented and I did not find one person who knew it well.
7. It fails a lot, in fact, I had to upgrade because the previous version became unstable.
This is not just my experience, it is a popular opinion when you search over the Web. If one company keeps working with Plesk, it is mostly because the cost of change is very high, but luckily for me, I saved more moving that tuning Plesk.
CPanel does not have any of the described problems, none of them.