If you are actually trying to edit a font in Illustrator, I don't think you'll have much luck as you won't be able to export it as a TTF from what I understand.
I do know that CorelDraw allows the exporting of TFF files, you may be able to edit the vectors in there without a problem...
What might be best, if you already have Illustrator, is to also get the program Fontographer (http://www.fontlab.com/font-editor/fontographer/).
You can work in Illustrator, export it as a EPS file, then import it into Fontographer and get your TFF file.
However, I read one person's account of the look appearing fine in Fontographer after importing a Illustrator 3 EPS file, then coming out messed up. But then again, this person was working on a Mac, using an old Illustrator file format, and then transferring to a PC. Fontographer has some differentiations when it comes to MAC and PC.