At least in Flash, you are warned that its missing and that the system will substitute. The font itself is somewhere in the firmware, but not having it should not affect anything you're doing ... I hope.
Mind me asking a question (again )?
I have Ubuntu+wind+Macromedia flash working but it is asking for a 'cowon gothic font'. Must be something Cowon made I guess. Is that font free/downloadable (can't find it on their website and not on iaf or abi