I suspect this is a media/burn speed issue. First of all, Memorex and Fuji are crap. There’s no nice way to put it. You get what you pay for. Secondly, the faster you burn, the greater chance of introducing imperfections in the burn that will be seen as errors by cheaper and less-capable players. My personal rule is to never burn 16x media any faster than 4x. 8x media goes off at 2x.
IMHO, if you use quality media (Taiyo Yuden, Verbatim) and use slower burn speeds, your disc compatibility rate will go way up.
-Jeff