Hi all,
my first post here...sure, i'm using XOOPS for a site like you.

Scenario:

Xoops 2.0.9.2 freshly installed on Linux Server @ Aruba.it ISP Hosting (in Italy is one of most famous, because is cheap )

I founded admin loop problem for 2 times and solved in 3 ways:

- removed all cookies and disabled Norton Internet Security (it had some settings against cached session... )

- chmod 777 /xoops-root/cache directory on webserver

- repaired MySQL table using "REPAIR TABLE 'xoops_session' in sql blank form @ mysql.aruba.it

I hope it's useful for the people who have same problem.

TNK YOU ALL FOR THESE SOLUTIONS...XOOPS WORK GREAT!