Say, I scroll down a bit to where the calendar is on the second week...it's
at the top of the screen now.  In about 5-10 seconds, it automatically
adjusts itself back to the top row being the first week of the month.

Also, if I'm typing in an item, about 5 seconds into typing it in, it
automatically quits that line.  If I'm in the middle of typing it still, I
end up typing it into a second item that pops up on that line.

It starting doing this several months ago while I was using Office 2000.  
Recently upgraded to Office 2007.  Still doing it.