Mutual Fund Account: How to modify Decimal Places

[Johannes Graumann]

Hi,

I created a mutual fund account tracking a depot containing a fund that is 
traded in 1/1000000 fractions. The fund is defined via the security editor 
with a fraction of "1000000", but no matter what I set in "Edit-
>Preferences->General->Numbers/Decimal Places", the ledger of the account 
doesn't allow me to enter values at the precision required. The "Shares" 
column allows 3, "Buy" and "Sell" just two decimal places. Any advice on 
how 
to fix that?

This is gnucash 2.2.9 on debian unstable.

Thanks, Joh