Reversing my firmware

I have had a good read and correct me if i am wrong, using dvrflash i should be able to revert my drives FIRMWARE REVISION back from 1.58 to 1.50, i understand that i couldnt revert from say a flashed to true pioneer back to an ACER drive. My drives i believe were bought as OEM pioneers, in that they came in plastic bags with no software, however i cant seem to flash them back to firmware 1.50 can anyone glean any info from the error ?? i can clearly see that it says this drive is not supported by this utility but why ?

C:\Documents and Settings\Administrator\Desktop\DVRFlash_v2.0\win32>DVRFlash -vf
g: R9100009.150 R9100109.150

DVRFlash v2.0 : Pioneer DVR firmware flasher
by Agent Smith et al., October 2004

                   DISCLAIMER

THIS PROGRAM IS PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND,
EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE.

THE ENTIRE RISK AS TO THE ABILITY OF THIS PROGRAM TO FLASH A
PIONEER OR COMPATIBLE DVR DRIVE IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
SERVICING, REPAIR OR CORRECTION.

THIS PROGRAM IS NOT ENDORSED BY PIONEER CORPORATION OR ANY
COMPANY RESELLING PIONEER EQUIPMENT AS THEIR OWN BRAND

IF YOU UNDERSTAND THE RISKS ASSOCIATED WITH THIS PROGRAM AND
DISCHARGE BOTH THE AUTHOR AND PIONEER CORPORATION FROM ANY
DAMAGE OCCURING AS THE RESULT OF ITS USE, PLEASE INDICATE SO
BY ANSWERING THE FOLLOWING QUESTION:

Do you understand and agree to the statement above (y/n)?
y

Commandline:
DVRFlash -vf g: R9100009.150 R9100109.150

Reading firmware ‘R9100009.150’…
fread(): No error
‘R9100009.150’: Unexpected firmware size or read error
firmware is of Kernel type (PIONEER DVD-RW DVR-109 1.50 )
Reading firmware ‘R9100109.150’…
firmware is of Normal type (PIONEER DVD-RW DVR-109 1.50 )

Drive Information:
Description - PIONEER DVD-RW DVR-109
Firmware Rev. - 1.58
Firmware Date - 05/08/09
Manufacturer - PIONEER
Drive is in normal mode.

Additional Drive Information:
Serial number - DLDL042521WL
Interface type - ATA
DVR generation - 0009
Kernel type - GENERAL
Normal type - GENERAL
Kernel version - 0003

The PIONEER DVD-RW DVR-109 is not supported by this utility - Aborting

C:\Documents and Settings\Administrator\Desktop\DVRFlash_v2.0\win32>DVRFlash -vf
e: R9100009.150 R9100109.150

DVRFlash v2.0 : Pioneer DVR firmware flasher
by Agent Smith et al., October 2004

                   DISCLAIMER

THIS PROGRAM IS PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND,
EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE.

THE ENTIRE RISK AS TO THE ABILITY OF THIS PROGRAM TO FLASH A
PIONEER OR COMPATIBLE DVR DRIVE IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
SERVICING, REPAIR OR CORRECTION.

THIS PROGRAM IS NOT ENDORSED BY PIONEER CORPORATION OR ANY
COMPANY RESELLING PIONEER EQUIPMENT AS THEIR OWN BRAND

IF YOU UNDERSTAND THE RISKS ASSOCIATED WITH THIS PROGRAM AND
DISCHARGE BOTH THE AUTHOR AND PIONEER CORPORATION FROM ANY
DAMAGE OCCURING AS THE RESULT OF ITS USE, PLEASE INDICATE SO
BY ANSWERING THE FOLLOWING QUESTION:

Do you understand and agree to the statement above (y/n)?
y

Commandline:
DVRFlash -vf e: R9100009.150 R9100109.150

Reading firmware ‘R9100009.150’…
fread(): No error
‘R9100009.150’: Unexpected firmware size or read error
firmware is of Kernel type (PIONEER DVD-RW DVR-109 1.50 )
Reading firmware ‘R9100109.150’…
firmware is of Normal type (PIONEER DVD-RW DVR-109 1.50 )

Drive Information:
Description - PIONEER DVD-RW DVR-109
Firmware Rev. - 8.58
Firmware Date - 05/08/09
Manufacturer - PIONEER
Drive is in normal mode.

Additional Drive Information:
Serial number - EDDL487867WL
Interface type - ATA
DVR generation - 0009
Kernel type - OEM_INT
Normal type - OEM_INT
Kernel version - 0003

The PIONEER DVD-RW DVR-109 is not supported by this utility - Aborting

C:\Documents and Settings\Administrator\Desktop\DVRFlash_v2.0\win32>

The problem was the revision of dvrflash, i followed a link in someones signature stating it to be the latest version (2.1) when in actual fact the latest is 2.1.1 and works fine now…i wish i could find the person whos sig it was so i could advise them.