fixed. it was actually pretty easy: your description of the problem reminded me that I hadn't re-implemented properly the horizontal scrolling due to lowest 3 bits of the hoffs reg
I had to remove it because to properly support it (without neither leaving a black strip on one side, nor writing beyond the last pixel) more boundary checks were needed in the tile drawing code and at first I was not sure where they would have fit... of course, I completely forgot about it afterwords
However, after all the small cleanups performed between 7493 and 7525, it was now fairly easy to fix the problem. Notice that this also fixed scrolling stars in the SNES Test Program!
In other words, I think there are no more known regressions compared to the old video code.
I will commit the fix as soon as I verify that it does not breaks anything else (e.g. OPT)
