@taos:
Ah, good point, I forgot to ask you in which context you were running this, and on which FW version.
KSM means it's running in shitty rotated 16bpp mode, so, higher potential for stuff to go incredibly wrong

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In the first case, I wouldn't mind an actual capture of the screen right after the broken clear. KSM bundles fbgrab, but it's probably old/broken, see
here for up-to-date standalone binaries

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(I say standalone because the in-repo one depends on a full tree (well, on zlib & libpng, but, still ;p).