changing security fraction traded

[brad]

I have a security for which I had the 'fraction traded' set to 1.   I
received a dividend which was reinvested & the resulting transaction has
a 1/1000 fraction.   I changed the security in the security editor, but
I can't enter the correct number of shares in the account.  For the 1st
try it took the fraction, but didn't update the balance.  I closed GC
and reopened, & now it won't take the fraction, it always rounds it
off.  
Suggestions?