If yes, make sure to set the Default Value to the value from the record set on the update page.
Yes I am using DFP and I know I have to set the default value. And I have done so probably well over 30 times including page do overs trying to get this to work. I have followed the steps in the documentation from this site over and over and over and over (times 30+) and once even took over 30 minutes to do an update form because I went so slow and precise to the documentation to make sure I didn't miss anything.
So that leads me to believe either the documentation has an error or it simply doesn't work.
I may have to do a Captivate video to prove it.