It would seem that burning at 52x other than on premium media like Taiyo Yuden is a bit hit and miss. Got some 52x Intenso’s here made by Prodisc here and burned at 52x they are iffy. At 48x there is no problem. No C2 errors and low C1 errors. At 52x however I more often than not end up with C2 errors near the end of the discs.
in my experiences 32x and 40x give the best results.
Intenso sells not-so quality discs. Not necessarily crap, but they can be.
CMC, Prodisc, DST are among the brands they have sold.
I remeber some Intenso Prodisc’s, out of ten four had huge scratches fresh out of the package…
52x is a very high speed even if the difference to 48x can seem insignificant. Lowering burning speeds may cost you plenty of seconds (but what are you going to use them for anyway? :p) but will almost always increase quality.
And you want your discs to last don’t you?