When they listed they probably didn't expect the price to be at half the IPO price so they would not have been considering the possibility of a buyback then.
It's likely the case that they discovered after announcing the buyback that the procedure was much more difficult than they anticipated, which is unfortunate and not something they can control. If they can't do a buy-back they need to just concentrate on the business and hopefully there's no impact on the ability to pay dividends (which is what I've been told).
I think it's worth buying a small portion at these prices, but not a high convinction buy.
XPD Price at posting:
9.8¢ Sentiment: None Disclosure: Held