I had a heat pump installed back in 09. Apparently their was an issue where the government got more strict in giving out grants> So I was informed that I would have to modify the system for it to qualify. Good Guys came out and replaced the indoor coil for free.
Since then I have heard other people who bought heat pumps have the same issue, but they had to pay for the modifications themselves or did not qualify.
My heat pump installation also looked very well done and their follow up was excellent.