Migrants to IJ, 2007

If I post another comment to the same thread, both appear when the page refreshes and I can delete the second one.

That, I've had happen to me over on LJ too. The actual missing-disappeared-were-there-but-now-not comments is IJ's glitch which Squeaky's trying to ferret out. It happens so infrequently in the scheme of things that they've so far been unable to pin down where the error is in the database to figure out how to fix it.

That's why opening a support request with a link to the post in question when it happens is so important.