Well, it's a minor trouble, but anyways, it might help me understanding the dynamics of the Start mosaic use...
I had it all 100% when, after trying to tinker with the Default Programs in the Control Panel, I made a bad decision somewhere. I clicked where I shouldn't, and then the link to the IE10 in the mosaic was lost (the blue one, 'official' to the mosaic)!
I can now only open it outside Metro, or open through a pinned web shortcut in the middle of the mosaic.
I tried triggering again the IE10 in the Default Programs, but it just *poofed* away.
Does anyone have any tips?