OK, the "Ebuyer" 48x brand CDRs are manufactured by Nan-Ya plastics. Although these are high quality they aren't recognised by a number of writers, I'm guessing the Philips is one of them.
I'd suggest you buy a trial pack of media from SVP or Bigpockets. I would hazard a guess that Ritek media will burn on this drive at the full 48x.
Alternatively you could buy a pack of FWS media from SVP. This is Ritek media and, now that FWS have had their batch problems sorted out, they are good value media. Hope this helps