Thank you for that file.
I can reproduce your issue using it. Specifically I can reproduce it using your "default" dictionary file.
It appears to be the blank lines at the top of the file, and a quick look indicates that the rest of the dictionary is ignored if it finds a blank line. How you got blank lines at the top I don't know, but we'll look into it. (EDIT: quite easily actually, since if you left blank entries in the list they would get sorted to the top...)
I noticed you had several dictionaries in the hunspell_dictionaries directory that appear to already be included in Sigil - so I was curious why you loaded them?
Last edited by meme; 10-27-2012 at 06:18 AM.