Then, I loaded the firmware A0814001.122 into the utility, cheked the "enable bitsetting" checkbox and saved it with the same name and in the same folder with pioneer R115D.exe flash utility.
But, the flash utility won't flash the drive because it already has the latest 1.22 ( original ) firmware.
So, how do I replace firmware 1.22 with patched version of 1.22?
You also need to load the *.exe flash utility (R115D.exe) in MCSE, patch it to allow same with same flashing and then you can used the patched flasher to flash your firmware without any problem.
Alternatively you can of course flash the patched firmware with DVRFlash ...