Again the Dual-Layer problem...
Ok, I'm going to try to explain this as well as I can, but that does mean this'll be quite a long post :S
Well, here goes nothing:
My Wii was hardmodded quite some time ago (year or... 2? 3?) with a Wasabi chip (Wasabi 3 I think), which was fine.
For burning normal games I use Verbatim DVD-R and they all work perfectly. No problems whatsoever.
But the dual layers... I found that for dual layers you need Verbatim DVD-DL+R, so I got those. I also found that the best would be if they were from Singapore. Sadly, I got them from Thailand and I sure hope that that is not the issue...
They were rated at 2.4x so that's what I burned them at. For the layer break values I saw people giving exact values (no idea how they got those values, although I would like to know), but also people saying that the ImgBurn 'calculate optimal layer break' function works (which I suppose it should, right?). Using that option I burnt a couple of DL games and they were recognized, booted and everything (at first).
I have Super Smash Bros. Brawl original so looking at that as a check, everything is fine. I might have had an occasional DRE, but it works normally for the rest. This should mean my Wii doesn't reject dual layers in general.
I have burned Metroid: Other M (actually finished this one with DRE every now and then, but it was still possible), Samurai Warriors 3 and newly Xenoblade Chronicles as dual-layer games.
They 'work' as in, it is possible to play them, but the more I play the more often it starts to get stuck and give me disc read errors. Now with Xenoblade I'm just stuck, because whatever I try to do, it gives me a DRE, either right after booting, or right after loading the savegame, or after walking or fighting. In general, whenever I DO something, it gets stuck. I tried Metroid: Other M again recently and for some reason it was now ridiculously slow with loading (I don't think it was that way before).
I tried cleaning my lens with the official Wii Lens Cleaning Kit. It worked for a while, but then after a couple of hours playing it just gives me more disc read errors. I tried re-burning Xenoblade, which worked for an hour or so... then I got another DRE.
Now my Wii is away for repairs as the internet told me that DRE's are often caused by dirty, broken or old lenses and my Wii was from the first generation with the wrong lenses I believe (bought it in December 2007 I think). But I got a phone call and he told me that my own Dual Layer game that I gave him to check it with (Metroid) didn't work (well), but an original SSBB which he got from another person does work (no wonder, because mine worked also).
So generally, I have no idea what's the matter then... The main problem is that my Wii reads Dual-Layers only slowly/poorly with more and more disc read errors.
Anyone got any ideas?