Question about why when I paid a $29 balance on a $300 limit to $0, my score dropped 10pts?
Are all of your revolving accounts now reporting a $0 balance? If so, you've been hit with the 'no revolving credit usage' penalty; points lost will be regained once an account reports a balance.
Edit: If what I posted above is not the case, and you do, indeed, have other revolving accounts reporting a balance, then the point loss was due to something else -- not this balance decrease.
myFICO alerts are not necessarily the reason for a score change. The alert just triggers a score update, which would reflect any changes since the last update- but the change in score may have no correlation to the actual alert received. Something else in your profile caused the score drop.