Unable to shut down MacBook

Sometimes when I go to shut down my macbook it states that an application cannot be closed, and only finder will shut down rather than the whole notebook (the menu bar at the top of the screen is gone but the dock is still active). At that point I have to hold down the power button to actually get the whole thing to shut down. What can I do to fix this problem? Is this a common thing or is it a problem with my macbook? Thanks guys!

i have had this happen to me one time -- i am running OS X 10.5.2. i think it might be a bug but i'm not sure. it might be fixed in the next update. does it happen often?

Not all the time but it happens enough to where I want to make a thread

I'm running Leopard btw.

Alas it does seem to be a problem - just have a look at this link and you will see Microsoft Office Synchronization Agent and .Mac are considered the main suspects.

http://forums.macrumors.com/showthread.php?t=378060