Teac CDR58s Bios



Since ive updatet my Teac burner to the Firmware 1.0n i cant burn with CDRWIN 3.8a on 8speed.My friend also bought a Teac58s and he has the Firmware 1.0k or 1.0 l on it
he copies on the fly without any error.
Here my question:Is there a trick to place on older Firmware on my Burner?
Everytime i wanted to that,the update utility from Teac says:You have a newer Firmware
How can i replace 1.0n with 1.0k or 1.0 l ?
Is there any other update program avaible?
And where can i get the older Firmware...?

Thanks in advance...