Thanks for the replies. I finally have time to pick up the subject again. I've checked my Philips DVD931. It has this line at the bottom: Philips '99-'00 7.22 010223 P9 3.26.7
I don't know which figure is the version no., 7.22 or 3.26.7? The firmware site has v7.12 firmware for DVD931. I don't know whether it is an earlier or later than mine. I don't know any method to backup my current firmware. So it is risky to try. Please help.
I reason I look for firmware upgrade is that the DVD931 seems having difficult recognizing DVD+RW (sometimes ok sometimes not but seems getting worse), DVD+R and DVD-RW (never ok). DVD-R so far so good. DVD Video always good. I think it may due to the fact that the player is older than these DVD standards. I hope a new firmware can help out on this.