[eluser]tomcode[/eluser]
I guess the multiple table entries are created because the session data is encrypted, try without encryption whether You still have multiple entries.
Using the database, I've found that user defined data is not stored in the cookie, but a default data set :
- session_id
- ip_address
- last_activity
For testing cookies I use Firefox with the Web Developer add on, it lets You see and edit cookies.