Post up your fonts subimages.txt file. The <SPACE> character in ASCII is character 32. Since you are on a Mac, perhaps this have gotten confused with another character (or just plain left out) in your font converter program.
Ideally your font subimages.txt file should look something like this:
---
32:247:255:25:51
33:550:153:10:51
34:467:0:19:51
(snipped for saving some space)
125:488:204:18:51
126:272:255:25:51
127:537:51:14:51
---
This covers all characters from space via numbers and lower and upper case A-Z plus a few other characters. With extended characters, it would run right up to character 255 in the ASCII set, which would add characters with umlauts for the nordic, german, french and spanish languages, amongst others.
The gist of it is, the setFontImage() command need the subimage.txt file to run from 32 to 127. If yours start later than 32, say at 48 (character 0), then if you try and use any characters between 32 and 47 in the ASCII set, AppGameKit will cut your text from that point onwards.
Here is a handy little ASCII chart for all standard characters:
