Where did you download the font from?
I downloaded
this one and it seems okay, I didn't see any problem with the little 'j' character on my Glo in the few minutes I tried it.
Edit: An unrelated problem with this font is that it uses a non-standard name 'lig' for the ligature substitution tables, so ligatures won't work in the ePub reader until you change the name to 'liga'.