Q: Since my update on Lion 10.7 I have a Problem with the login

Since my update on Lion 10.7 I have a Problem with the login.

The loginscreen appears,

For a few seconds the cursor is blinking in the passwordfield.

Then the screen freezes and I get the beach ball.

At least I get a kernelpanic.

If I am quick enough typing my password I can start my macbook.

It also works if I switch to automatic login.

anyone an Idea

Thanks a lot