Be sure and run your messages.txt files through Hebe's "mySH3-TooL_v1_9" at the least, or a favorite tool of your own choice, to check for proper conformity to SH "standards". We had messages in FotRSU that would not "show", or display in our mod. Hebe's tool pointed out that the dash character ("-") is not valid in certain locations of a message, and if it was in a message, it would only display the text "Message content", which is the "header" of the comment column at the top of the file. I am certain you are aware of the way dates work in the file also, but be sure and double-check yourself there also... Just sayin'...
- and yes, I am guilty also.
By the way, this is definitely a plug, and endorsement of Hebe's mySH3-TooL_v1_9 tool... lol