Problem with the Pioneer 110D

I just both the dvd recorder and I already burned a dvd without problems. The problem that I have is that the drive doesn´t read some CD´s. I have to download a firmware? which one? I saw that are 2 different types of some versions: (DK,SV) or (BK, SV) I don´t know which one i should download.

the abbreviations in the brackets refer to the colour of the drive afaik. the correct firmware for the 110D is http://wwwbsc.pioneer.co.jp/cgi-bin/www1/download/file_get_e2.pl?file=DVR110D_FW139EU.EXE