SharePoint 2010's April 2014 CU introduced a bug with copy and paste. 

Bform.debug.js 381,869 11-Feb-2014 12:37
Bform.js 249,012 30-Jan-2014 16:39
Form.debug.js 211,134 11-Feb-2014 12:37
Form.js 126,783 30-Jan-2014 16:39

 

This was fixed and released in SharePoint 2010's August 2014 CU.
http://support.microsoft.com/kb/2760757

Bform.debug.js 381,888 15-Jul-2014 11:17
Bform.js 249,022 15-Jul-2014 11:17
Form.debug.js 211,153 15-Jul-2014 11:17
Form.js 126,793 15-Jul-2014 11:17

 

Story

On December 10, 2014, before we patched to the August 2014 CU level.  A certain very naughty person (me) couldn't wait and decided to offer a quick hack to the Javascript for the users over the holidays.  He even did a bak backup file of the original Form.js

 

 

We have now applied the August patch, but unfortunately, you can see:

bform.js, bform.debug.js, form.debug.js all updated.

Form.js is NOT updated.

Copy and paste still doesn't work in our environment.

 

Oops.

 

While a cheating way would be that we install the patch on another environment, and copy the correct Form.js file over. 

We'll be experimenting in this dev environment to see what is the best way to revert and go back to the supported path.  Stay tuned for a follow up article.