If only there was somebody somewhere in the government who understood the first thing about economics they might realized that paying people to buy houses only drives up the price. It doesn't help first time home buyers - it helps existing home buyers.
Let me explain this slooowly. Prices are set by supply and demand. Increasing demand (through tax breaks for purchasing a home) will cause the price to rise. Since prices for houses are already set to whatever the market will bear, this tax break is a subsidy for those who already have a house as it will increase the price they get when they sell it.
If you want to help first time home buyers, stop trying to increase demand and instead increase supply, or, given that we already have too much supply, simply stop trying to increase demand and then stand back and let prices fall to their natural level (i.e. the one people can afford without subsidies from the government).
Update: I should add that if we were talking about some easily manufactured widget, then an increase in demand might just mean making more for the same price to meet the demand. But houses don't work like that, house prices relate more to what people can afford to pay than they do to the cost to build them.