Drupal: session variable is lost when not logged in

I have a module in Drupal 6 that saves some information in the $_SESSION array. I use this information to customize some content in another page.

The problem is that when I'开发者_运维技巧m not logged in Drupal, the information is not saved in the session. When I'm logged in, it works as expected.

Any ideas? Thanks.

Found the answer here. There must be an user with uid = 0 at the "users" table. For some reason my project didn't have one, so I inserted it manually and the session variables are now being saved.