CB Connect, Factory 500 page appears after login

my website: bioscent.biz

problem:
I can login using the super user account, both by typing in username-password or using the connect button, but for every other users it just go to the factory 500 page, no matter which login method is used.

Any help on this problem is greatly appreciated since I have been searching everywhere and found no working solution.

thx

since there's no reply yet and I am in a hurry, I scrapped everything and started from scratch (as in , deleting the account from whm, then recreating it).
right now, the login is working, but I have not put in any content, yet.
will post again if problem resurfaces