Odd arithmetic in ledger

[Jack]

During my last reconciliation, I just couldn't get things to match  
compeltely, and I finally found the problem.  I have two deposit  
transactions in a row, where the first one seems to add one cent too  
much to the balance, and the next one adds one cent too little.  If the  
first of them wasn't the last transaction in the problem  
reconciliation, I probably never would have noticed.  These are in a  
brokerage account: the first is an interest transaction, so there is no  
rounding done at all.  The second is a dividend transaction, so there  
is also no rounding done.  I'm attaching a screen shot, just to show  
I'm not making this up (for a while, I thought I might be.)  Can anyone  
think of any possible reason for this behavior?  All accounts involved  
are in US dollars only, so there is not currency conversion going on.

Thanks for any hints.
Jack