I have a Phillips DVDR80, and 10 days ago it suddenly refused to load the Phillips 8x DVD+R disks that it has always accepted up 'til now. The machine gave no error message, but kept ejecting the disks (I tried quite a few).
I phoned Phillips customer support and was assured that it was a fault, and I would have to return it to them with a cheque for £85. Since they no longer carry spare parts for this machine (it's only 2 years old!) they would "probably" replace it with a newer model, but I would have to pay first and wait and see what the outcome was.
Since, if I was going to have to pay more, I would prefer to upgrade to a machine that included a Hard Drive, I opted not to pay good money after bad, and bought a Panasonic EX75, which I am really pleased with.
Anyway this morning, having read your original post, I went to the Phillips web-site, and burned the latest firmware onto a CD-ROM, and put it into the DVDR80, and guess what - it now works again!
Quite why it would suddenly refuse disks which it has always accepted before I don't understand, but before writing off your machine, I would strongly recommend trying the firmware upgrade.
I used a 30-day trial version of Nero that I got from the Nero website - with which it was easy to set up the options listed on the Phillips website.
Then it was just a case of inserting it into the recorder and waiting while the upgrade took place.
I'm still mightily annoyed at Phillips tech support though for telling me the machine was broken when it obviously wasn't.