A balance decrease will never lower a score 4-9 points. Both of you above that saw 4 and 9 point score drops, I can assure you your balance decreases were not the cause. Perhaps you're using a CMS that provides you with "alerts" and you received an alert that one of your balances decreased. At the time of the alert you're provided with a new score, but it doesn't mean that the new score has anything at all to do with the alert reason. This is a very common topic on this forum.
The only time a balance decrease will result in a score drop is if it's your only account with a non-zero balance and you go from that non-zero balance to a zero balance reported. In doing this though, one typically will lose to the tune of 15-20 points. This is why I say that a 4-9 point drop would be impossible from a balance decrease.
A great suggestion that CGID has been making a lot lately is to focus less on the score and more on your reports. Have you pulled your before/after reports? In looking at them 9 times out of 10 you'll be able to identify the real reason for your score shift.
