Hello
Sorry, you've been waiting so long for reply.
Make sure, that title text is free of spelling errors (typos, grammar structures).
Additionally, check in AdminCP, whether your forum uses selection 'allways trust user' in translations. If it does, and user doesn't set default language in his settings, translation engine won't recognize a language of the message and such an issue may occur.
no answer - solved. If not, please write here and I will open this thread again.