Yeah, same thing happened to me on the first gearbox. 1st to 2nd and bang....bye bye 2nd gear, then the shrapnel killed 3, 4 and 5.....
They told me the warranty replacement 'box cost $7700 and that they wouldnt be so nice, if it came back broken again and that it was the worst 2nd gear explosion they had seen.
The second box went (diff and axles let go). That one cost me $2700 to fix, when Holden denied warranty due to "abuse". But the box has now been rebuilt with new internals and greater oil capacity, as the people who fixed it for me, said that these Astra/Barina SRi boxes run very low on oil from the factory and rely on a "splash" system, rather than a direct feed to the bearings and crownwheel. Mine now takes an extra litre of oil so it wont be breaking anytime soon
The 1.8 litre Astra/Barina SRi gearboxes are breaking 2nd gear at the rate of 1 or 2 a month (from what I have heard from people I know that work at Holden)
You can, however, get a 6 speed sequential, dog engagement gearbox with LSD and billet axles from Quaife in the USA for "only" $28,000 (landed here), which is actually $1000 more than the car costs to buy (incl ORC). Hence, why FWD's are hella ghey