How can I get ・, ー, and ꜜ to display at the same time?

I’m writing a text, mainly in English and Japanese, but it includes Chinese and IPA as well. Normally, Writer handles it without problems, but some special characters (not Chinese characters) have started displaying incorrectly, seemingly at random. It’s always the same ones, too: ・ (a common mark in Japanese), ー (also common in Japanese), and ꜜ (IPA downstep). The two first marks, ・ and ー, stop displaying at the same time, leaving the error glyph that looks kind of like 口. Whenever they do display correctly, ꜜ turns into the error glyph instead. I noticed that the problem started after I first used the ꜜ , so I suspect it’s related to that somehow. I’ve tried changing the font to Droid Sans Japanese, since it seems to support every character I need, but the problem returned within two minutes. Is there anything I can do to fix it?

SOLVED! Upgraded LO, and the problem was no more.