yea, the bar is original, but fifth line doesnt has any kind of knot to change its lenght... in the in the Y of the fifth line of the kite where u connect your line of the bar, there is only one knot, and not 2 or 3 like torchs from 2007 to 2010, 2011 i didnt looked...

I think i would do some extra knots in central the lines of the kite where u connect your lines of the bar, and then, the central lines will be reduced, but i dont understand why the original bar 2012 with its original kite 2012 make the kite collapse or stall with the bar down... and not with the 2010 bar...

That sounds about right. Mine flew perfect with one knot. Make sure everything else is good. On fully sheeted in the wingtips are slightly pinched. Not much tho

I would go query that with the shop you purchased the kite from. Ask them if you can borrow another 2012 bar (demo bar) and see if the bar you have is really the issue. If you do not have a shop near by maybe another 2012 bar owner from your local spot could let you test their bar.

My 2012 bar worked perfectly with my 2012 torch. I did not notice any knots on the center line either for adjusting length. You could tie a figure of eight knot or two close to the connection point in the stitched part of the line to shorten it but that's not going to help you if you need to lengthen it.

Have you read the owners manual http://www.naishkites.com/2012/downloads/pdf/2012NaishKiteManual.pdf (size:25MB) section about tuning the kite. The manual should have come in a printed copy in the kite bag.