It looks like a font problem. In particular, I see that you are
rendering without anti-aliasing, and many TrueType fonts support
bitmap rendering only in a PPEM small range (if at all). Use a font
editor or font dumper to check the `gasp' table of the font to find
out the supported ranges.
I'm using freetype2 on an embedded device. When I run my application
on device with 7-inch display all the glyphs are rendered fine [...]
If I run the same application on a device with 9-inch or 12-inch
display some glyphs (V, v, Y and y) are not rendered correctly.
It looks like a font
