Had this problem with a new install of 2.6.5. (Not that I believe it is a WB issue, but rather a server/php issue).
I ran into it straight away when I tried to install WB.
Solved it as follows:
1. created a "/tmp" directory in my WebsiteBaker installation and made sure it was word-writeable.
2. modified the index.php file in the install directory as follows:
just before it tries to start a session on line 29, inserted code:
*/
ini_set("session.save_path", "/home/strategy/public_html/portfoliowatch/tmp");
ini_set("session.save_handler","files");
ini_set("session.use_cookies","1");
Obviously, the path that you see in the first line needs to modified to correspond with your path.
This solved the installation problem.
I then ran into it again when trying to login as admin or trying to view the site normally.
To fix that, modify the file "initialize.php" file in the framework folder in the same manner. The session gets started on line number 54, so just insert the same code just above it.