I wonder if you changed the font style in your gtkrc file it would work?
Believe it was Saulgoode that showed me this trick to change font size and type for tutorial clarity.
style "user-font"
{
font_name="exact name of the font you want here"
}
widget_class "*" style "user-font"
This is mine ( the numeral 10 is the interface font size ) "comic sans ms" is the exact name of the installed font.
style "user-font"
{
font_name="comic sans ms 10"
}
widget_class "*" style "user-font"
Not sure if it will work to force Gimp to use a different font but it's worth a try.
