Comment 1 for bug 535371

As nothing was designed to operate like that, here's my guess: strings that disappear are probably "almost identical" (i.e. a typo, punctuation or spacing is different) to a human, yet it's not to a machine. Thus, these translations don't get reused, especially since LP drops fuzzy translations (because they sometimes give very bad results). This happens very commonly with PO files generated from documentation (long paragraphs, etc). We'd like to improve this part of LP, but we still haven't had the time to do it.

If this is not it, it's a pretty strange bug, and it'd help us if you can have those translators point us exactly at the message (URL would be perfect) that they translated and which later disappeared. Please re-open the bug once you have more details.