Ah. I misunderstood you. I thought you wanted to edit on the n900 itself. On ubuntu, I've only tried avidemux, but had a different mileage than you. I am not at my private desktop now, but will try this at home tonight, as it's a bit weird that an older version on my n900 would be capable of doing what the newer ubuntu version would not be able to do.

I'll report back.