ive encountered the same problem.
i got a toshiba sdr5002 with region free firmware x031
discinfo says no lock detected.
all dvds play fine from any region inc RCE encoded ones
but my battle Royale DVD from hong kong - its a region 3 one dvd9
just dosent get recognised
also my naked killer hong kong ones the same & thats region free (& dvd5)
so i cant see a connection…
other hong kong dvds play ok, just these 2 out of about 50+ discs.
(the access light just stays on)
id love some help, besides this little problem this writers the buisness, cds burn 16x never had a coaster
& dvds - never had a coaster either.