I am not experiencing the same, but let me guess a bit:
I suppose, you are expert enough to watch over the space on your HD. How much is left? 20 % free space would be good. Did you try to start with the shift-key, which disables in Lion the start options? Are you able to start like that?
Do you repair regularely your permissions? http://support.apple.com/kb/ht1452
Could you look into the error log with Console please, (Applications > Utilities), and look for some conflicts at start up?
That's all for the moment
Thanks for the response!
1) I have about 90 GB of free space out of the partitioned 249.2 GB.
2) I have not done that until now, and it turned out with a lot of errors. It seemed like it managed to fix it though. I will try to do some reboots and check if there is any improvement
3) What am I supposed to look for in the console?
I forgot to mention it i my initial post, but I guess it is worth mentioning; I used the "TRIM enabler software" to enable trim. Might that have anything to do with it? I mean, the computer works perfect exept for the start ups.
I did some additional findings:
1) When I disable the automatic login, it boots without problems.
2) It actually freezes every try if I don´t punch in the password and hit enter within approximately 8 seconds after the login screen appears.
3) The CPU ballons when it freezes, because when I manage to login after a few failed attempts, the core temp is 70-80 degrees celsius.