Bought a Liteon 48246S about 2 weeks ago and have been very happy with it, fast and burns great, havent had any problems with it. But at the end of the day we can't say that every Liteon CDRW that comes out of the production plant is 100% perfect, sometimes its just the luck of the draw. But for me I am very very happy with mine, no problems what it.
Also have a BenQ CRW 4012A, and very happy with that burner as well, have it sitting in my home server and has been a great burner.
Though I havent flashed any of my burners as I personally dont really find any need for it.