This is now officially weird.
The other tournament didn't show up yesterday or today, I checked it from the Elephant at the same time I wrote the original post. After that I played one tourney and then checked what the Full Tilt Poker's hand history directory folder says and saw one file mentioning husng, duration less than five minutes (as Elephant claimed the average was over nine). And now that I returned to Elephant again, the other yesterday's tournament has magically appeared there and the average duration has been fixed to 6:47.
I can't really figure out what could cause a single tournament import to be delayed by a whole day, it's the same import mechanism regardless of whether I start Elephant before or after playing the tourneys (yesterday after playing, today before).
Oh, and I'm running XP on Virtualbox, though I don't think that has any effect in one way or another.