[Pao|o]

I turn it on.
It boots up properly enough
It gives me the login name.
I place the in the password
Clicked "Log in"
It log's in and I'm presented with the blue curvy background.
It takes some time and the arrow doesnt turn into a beachball.
It becomes the simple light blue background
I come back to the login window where you put the password again.

Anyone have an idea I can fix it?

[Nivag]

can you safe boot into your macine? hold down the shift key until you get the login screen, which should say Safe Boot in red above your login name.

the will start your mac without anystartup items.

more info here

http://docs.info.apple.com/article.html?artnum=107393

[Pao|o]

Cold booted and pressed SHIFT til the grey & Apple logo appeared then released.
Saw the "Safe Mode" plastered on the Windows login
Logged in
It is now in the light blue background longer. About 5 mins na.

The arrow doesnt turn into a beachball

[Thinine]

Sounds like WindowServer is crashing and kicking you back out to the login screen. Weird. Check and see if you have any login items. Also, have you installed anything lately?