Did you record on +R or +RW? If recorded on +RW, you can change the compatibility bit on the +RW to a DVD-ROM setting which might permit the DVD to play on your Sony. With the DVD+RW in the Philips tray (and with the tray open), hold down the '2' button on the remote until the tray closes. If that doesn't work, try the same thing using the '3' button on the remote. Using the '3' button will change the compatibility bit to a
DVD-R setting.
If the above doesn't work, go to a Circuit City and try the Philips-recorded DVDs on each of their DVD players until you find one that plays it. I have found the greatest compatibility with Apex, Panasonic and Sony DVD players.l
Good luck,
Jim