MacBook freezes after booting

Hi,

since a few months my MacBook freezes after booting. This problem happened almost every day on the first start-up a few weeks ago. I found out, that my hard drive had small problems, but I was able to fix them by using the Recovery HD. I thought that would have solved my problem, but it happende again.

After a freeze and a second start-up, I checked the console and found the following message:

"kernel: nspace-handler-update: did not find token 272"

Other appearing token numbers were 366, 438, 437 and they only appear in the console after a freeze.

Does someone know what this message means and how I can fix the problem, so that my MacBook doesn't freeze after booting anymore?

Alex

EDIT: I can see the desktop and move the cursor when it freezes, so no blue screen or something like that.