I've started to use tuxGuitar and I'm positively impressed, nice program!
I was surprised with one point: I want to repeat twice a couple of measures and used the corresponding delimiters. I was really surprised to see the indication "2x" above the "close repeat" marker.
In my opinion, it's wrong: I've never seen any score with such a "2x" indication. The number indication is written ONLY if this part has to be repeated more than twice. The indicators ||: and :|| means per default "repeat twice" and are enough for that.
Just as example: a screenshot from tabledit:
http://www.tabledit.com/images/carbon.gif
Oups, I've been playing with the program last night and I've notice that my remarks was not precise enough. Usually the number above the repeat mark is the number of times to play the part, not the number of replays.
So more clearly:
|: :| play it twice (replay once)
4x
|: :| play it 4 times (replay 3 times)
I believe the current notation of tuxGuitar is not conventional, a bit unexpected.