The changes that are getting lost &mdash; are you sure that Deep Freeze is off (computer is thawed) when you install them? BTW, Russ came up with a simpler way to bring up the DF password box: hold Shift and double-click on the polar bear icon in the system tray.

It's not the answer you need, but the <i>supplied</i> dictionary is in "C:Program FilesMozilla Firefoxdictionaries".  It's got a basic words file and an affixes file, but the format (altho plain text) has some rather opaque notations in it and I wouldn't relish trying to safely edit it by hand.  And anyway it's not where words get added when you approve them from the editor:I added some words today but the files in the path above are still timestamped from the program installation.

Are the students using individual logins? If not, you could get your words added by acting as though to post the list in a blog, letting the firefox editor flag them, and choosing Add to Dictionary manually for each. (And I'm just assuming that this would be per-user.)  Of course, don't forget to thaw the computer first.

If Erin or anybody else reading this wants to track the spellcheck files further, you could look through the routine specified in "chrome://global/content/inlineSpellCheckUI.js" for clues.