Hello , I am new in this forum ,come from Austria and i am with enthusiasm from this forum
I had update my F9210bt with the new cnsd-210 . Now it is impossible to use the hackmode. Testmode is all right.
I had the same operation (testmode, hackmode) like befor the update. Have anybode an idea ?? 
Many greetings from Austria/Tirol
There are two ways to use hackmode in updated unit.
Easiest method is to:
1) always make backup of PRG0, PRG1 directories!,
2) delete PRG0, make another copy of PRG1 and name it as PRG0,
3) delete PRG.FLG file,
4) apply hackmode like always.
It doesnt work now, because after update unit creates file PRG.FLG - empty file,
if PRG.FLG file exists on the unit, then it boots PRG1 software,
if not - then uses PRG0. Its just some kind of 'switch' 
Update changes/modifies other than used at present PRG directory.
For example when you will update your unit with future firmware update,
then it would propably modify PRG0 files, and delete PRG.FLG.
br
condi