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It is a well documented fact that Memorex Branded Media in many instances is poor quality problematic Media.
It is also a well documented fact that Matshita/Matsushita/Panasonic SlimLine (LapTop/NoteBook) Drives are extremely Media picky Optical Drives and require the use of known proven high quality top of the line error free Media such as Taiyo Yuden or Verbatim Media. Attempting to use any lesser grade Media will only result in less than desirable results similar to what you have experienced in your attempts to use your Memorex Branded Media.
I second what [B]bjkg[/B] said.
My Matshita UJ-840S (not 850S) is extremely picky about DVD media, and the best I have found for this drive is Taiyo Yuden 16x DVD+R media (media code YUDEN000 T03).
My drive also burns with poor quality when using the maximum burn speed (8x) so dropping burn speed down to 6x or 4x can help in many cases.
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