See bug report filed here:
Note the initial bug report got 'fixed' but that fix introduced this new error, so the issue was reopened a few days ago.
Anyway, it looks like the team might have bigger fish to fry at the moment - thanks to anyone who does find time to work on it - but in the meantime, can someone suggest a good workaround? I was hoping to just edit the geotiff in gimp and do a color map from #000000 to #000001 or something, so that the 'almost-black' areas are no longer picked up as transparent in qgis - but, the file is too big (it's a labels layer from a USTopo) and gimp crashes in addition to complaining about some data fields on reading the file which kind of indicates the output may be dodgy anyway.
Is there a gdal tool to map colors in a geotiff? Or, some other script or program that anyone could recommend?
Thanks in advance.