Again, I'm in Leo right now, but spent the last hour searching for it/them.. no soap.
So I added some real long names to it, they showed up in en.
I made a new file in Text Edit with these words...
qwerty
asdfgh
zxcvbnm
Changing one slightly to zxcvbnmkl and highlighting it in Text Edit, Right Click>Spelling & Grammer>Show Spelling & Grammer... it shows that zxcvbnmk is the proper spelling... en was not changed, as it was with the real long names!?
zxcvbnmk does not exist in the content of any file, I have not found a Folder or File that was changed on those last three words!?
I don't know how long of list you have, but a possible workaround...
Load/paste them all into Text Edit, Select All>Right Click>Spelling & Grammer>Show Spelling & Grammer... Click Learn repetedly... I did a list of a hungred or so this way.
Assuming Tiger has the same capability I'd guess.