There is an option "Print Invoice Date same as Ship Date" - sounds like somebody said Y

If you are now in April, the AM-A Close Date should have been set to prevent transactions in February.  That said, there was a change made to the date processing based on user requests on the forum to pull the line 1 ship date for invoices if you said Y to use Ship Date for Invoice Date and a Ship Date had not been entered in SO-E.
 
I will send you a further refinement (about to be released) that more clearly allows entry of invoice and ship dates separately.

I don't understand how you can change the date on a posted invoice.  I don't have the latest update yet, but I can't imagine that would change-- When  you are reprinting a invoice that has been posted there is no choice about what date to use.  It uses the date of the invoice.  
If you are reprinting an unposted invoice however, you can change the date.  But why would you ship something in February and not post it until April?  Is DBA  using the OrderDate?!?
 

Reprinting the invoice is not changing the date.  However, the posting may be picking up the Ship Date rather than the Invocie Date and making that the invoice date.  Mike, I just sent you the further refined version of SO-F that should be saving the dates properly.

We have chosen to correct them by deleting them and redoing them with the new menu.  What was interesting was that when these were originally printed, the upper right date on the form was the date of the print.  If you reprinted it, that upper right date changed to the ship date.  Also, on the older version of SO-F, if you said no to "print invoice same as ship", hit enter to the invoice date, hit enter to the ship date, the ship date would show the present date (and we assumed it was applying that date - but it was not).  Anyway, the new SO-F works just fine (at least with the way we use it).

Don't know if this is related but after installing the update we are experiencing problems with the invoice date.
The Print invoice program date is 4/24/07.  
The first question is invoice date same as ship date, which I presume is the ship date entered when the SO was released.  WE always enter Y here.  The next field has all 00's for the date. The next field says use existing SO ship date?  We would enter N here, since we want to use the Ship DAte entered when the SO was released.
When we entered N here, today's date popped up in the next field, and when the invoice printed, it changed the date to today's date, even though we asked it to use the ship date, which used to be 2 days ago. We had to go back into release sales order to change the date back.
 
Next we tried this:
Say Yes to invoice date same as ship date. For the next question, we are able to enter  Y here also, and the SO Est Ship Date pops up in the next field.  Now I have two different dates that are going to be used!
We haven't finished testing this out because the example we were using had the same SO est ship of 5/11/07 as the Ship Date- 05/11/07.  So it looked okay, but not sure which date it used.  
As soon as I have results that can tell me which date it uses I will write again.
 
But the first way is how we have always done it and now it doesn't work.