ah dear. Can i ask, did you disconnect the battery before changing over the dash lights? If the answer is no, that may be your problem.
I vaguely remember reading a post on the topic of painting the dash fascia, and remember a story of a person who'd taken it out and disconnected things behind there without disconnecting the battery.
When he chucked it all back together, airbag light wouldn't go off, had to take it to an auto elecy. Good news was the auto elecy had it fixed up in about 1 minute and no charge, so i think it's a case of plug in his device and chuck out the error code. Don't take my word for it, but i believe this MAY be the problem.
i have same prob, air bag light comes on when u take dash out and turn the key to start of something, as previously when i changed bulb without turning the key it never happened...just have to find the time for an auto elec or holden to fix for me.
I had this problem ages back, problem was wire that comes from airbag down steering column, the plug wasnt in properly. from memory, you have to take column shroud off to get to it. let us know if that helps.