LastNum Column Behavior

[Cheryl Wheeler]

I noticed the following odd behavior in Gnucash:

I have the LastNum column displayed in the main chart of accounts. I 
added a new entry in my chequing account for a cheque that I wrote, but 
forgot to enter the cheque number. I
later edited the entry to add the cheque number, and the number was not 
updated in the LastNum column in the chart of accounts (the previous 
cheque number was still displayed).

Saving, closing, and reopening the book did not cause LastNum to be 
updated. I was able to fix the problem by duplicating the entry and then 
deleting the duplicate.

Is this a known issue? Gnucash 2.6.12, Windows 7.