Adjusting "Type" in AP transaction locks transaction

[Duane Evenson]

If I change the "type" in a transaction in the Accounts Payable window 
to "I" (Invoice), the transaction becomes uneditable. I can't change 
anything in the transaction thereafter, either from the AP account 
window or from the corresponding other account windows. I can't even 
change the type to "P" (Payment) to fix this. If the type is "P", I can 
edit the transaction.

I'm running 2.0.0 (gnucash-2.0.0-1.fc5).

The only workaround I've found is to duplicate the transaction, delete 
the original, edit the new transaction and only then change the 
transaction type setting. (I'd mistakenly locked a number of payments as 
"I" when first setting this feature).

I know the first thing some will say is upgrade to a newer version, but 
this version is stable, does everything like I want it -- until now. 
Besides, if this is a feature and not a bug, I'll encounter it in later 
versions. My first bet is on human (my) error and some friendly 
instruction is the easiest fix.

TIA