Simulator is able to draw numbers but not letters

I've been trying to debug this for hours.. I have this code:

dc.drawRadialText(
halfScreenWidth,
halfScreenWidth,
Graphics.getVectorFont({:face => "BionicBold", :size => 26}),
"1234",
Graphics.TEXT_JUSTIFY_CENTER,
180 + 30,
halfScreenWidth,
Graphics.RADIAL_TEXT_DIRECTION_COUNTER_CLOCKWISE
);

This works as expected.

If I replace that "1234" with "BATT", it doesn't draw anything!

I tried a few other strings. It looks like it can only draw numbers. Anything else will draw emtpy.

How is this possible? I'm about to lose it....