Starting Moneydance 2012.2 (842) at Tue Dec 04 09:32:12 EST 2012
Settings Folder: C:\Users\Kevin\.moneydance
Platform Handler: com.moneydance.apps.md.controller.platforms.WinHelper@604b7b51
OS: Windows 7 6.1 amd64
Java: 1.7.0_07 (Oracle Corporation)
Is in sandbox: false; restricted file access: false
should open last known file: My MoneyDance
opening internal book: My MoneyDance

Dear MD Support,

A little background...
I download txns from Fidelity into a regular investment account.
In this example, the txns are a Dividend txn and a Reinvestment of the dividend txn.
(a Div and a Buy)

So as to cut down on the number of txns in my register, my standard routine is to change the Buy txn to a DivReinvest txn and then delete the Div txn.

To recreate this bug:
Modify the downloaded Buy txn to DivReinvest, Hit ENTER.
Click on Edit > Undo.
The Modified DivReinvest txn reverts back to a Buy txn however the txn no longer reflects the cost of buying the shares in the Cash Balance column.
I'll supply screenshots if necessary.

-Kevin N

Edit:
This condition is also present in the following environment:
Starting Moneydance 2011r2+ (808)
Settings Folder: C:\Users\Kevin\.moneydance
OS: Windows 7 6.1 x86
Java: 1.6.0_21 (Sun Microsystems Inc.)