Do you have more than one stars install location? Did you ever before? Check for .eu, or any other country's software installation. If you are not playing on more than one, uninstall the other, and delete the c:\user\username\appdata\local\pokerstars.xx folder for that corresponding version and delete the c:\programfiles folder for that version. If you previously had one installed, check in the appdata folder - there probably is still a folder. Delete any for sites you no longer use.
If you play on multiple sites, make sure they have the same seat preferences set and Please turn off auto center in Stars' options, for all seats. Please see this:
http://imageshack.com/a/img534/4143/783.gif
If you still encounter a problem, close HM and Stars. Add the Stars appdata folder from above to these steps as well:
Please see this FAQ to alleviate any security bottlenecks:
http://hm2faq.holdemmanager.com/ques...olders+HM2+use
Delete the c:\programfiles\pokerstars\user.ini file.
Now restart Stars and make sure your seats are assigned. Then, open HM2. If the site setup has preferred seating set, then all is well.