The current smartcard package only works in the Dublin commuter zone, it opens every turnstile IE have in place - its still really under test to some degree. The more complex point to point rules have yet to be tried in public.
We have submitted some ideas to IE to address this issue, the simplest being to stop rewriting the mag stripe every time it passes through a machine. This could make a huge difference. Also never ever use the validator on the bus, they then to feed off annual tickets
I understand investigations are continuing to trace the exact reason for the high level of ticket failures and various things are being ruled out.