i have a macbook and i does not go into safe sleep after i forget to put in the power cord when the battery was low.

what happends is that it goes into safe-sleep but then when i put the power cord back in the grey screen comes up but then it goes black and then goes back to the grey screen and then the apple logo comes up and the little turning thing....

i recently ran main menu (http://www.versiontracker.com/dyn/moreinfo/macosx/25902) and ran most of the things of there to clean up the macbook

could this be why? if not then any other ideas as to what it could be