Partial Source: Prowrestling.net
When TNA announced that they were taking iMPACT! on the road and doing double tapings, it was stated that the promotion would pay talent per date, and not per episode they appeared (unless other specified in their contract). This meant that a talent could work the live episode and then the taped episode, and only get paid once.
According to sources, TNA is now paying per episode, which has made the talent much happier. The talent was informed of the change at the Corpus Christi tapings back in April.