Philips dvdr -72 dvr - disc error message?

Hi I have a Philips DVDR-72 dvd recorder it has worked well until very recently! Lately I keep getting ( DISC ERROR ) messages on the led panel /display nearly everytime I try to record ! Either the deck locks up during recording then goes into Post format? message and showa to be still in record mode but time display stops Or I can record a whole movie to the disc and then it does the same thing ! Ironically These disc error recordings will play back on regular dvd players fine assuming the player can play DVD+R Media . I am hoping the problem is just crappy media PHILIPS DVD+R 2.4X although it has has happened with memorex DVD+RW media as well ! When I first bought the unit I had some VERBATIM 8X DVD+R media which worked very well perhaps I should use only these disc? Also let me state that the media I am using is mostly from freshly openend packages as well as previously opened packages if tht makes a difference ? If anyone else has the same problem I would like to know how you fixed it ? thanks again Peace & Happy burning!