@ the watcher
Those samsungs probably have a Media IDentification code(MID) of OPTODISCR008. They most likely are listed in your firmware to burn at only 4x, as with the newest/best 1633/1653(they are basically the same drive) firmware. What firmware does your drive have? A fast-and-easy answer for you would be to get better media that will burn at 8x and above. You can check the CS0M thread to see what others have had success with. Here is a good place to cross-reference between MID's and Brand names.
A longer, more involved answer...you could flash your drive with the newer firmware CS0M, then load your firmware in OmniPatcher and swap the strategy for OPTIDISC016, which is set to burn at 8x, and see if you get good results. Merely checking the 8x box in the OPTODISC008 strategy usually doesn't produce good results, but you could try it.
This post has probably raised several questions for you. Check out the FAQS, where you will find many of these answers. There is a lot of knowledge there and on the forum in general, so take your time and read up on what to do. Flashing your firmware to a non-official firmware will void your warranty. Understand what you are doing before you do it.