Hillsborough County home buyers were more active this February than last, a sales pace helped by housing prices that eased a bit year over year. The Greater Tampa Association of Realtors said Hillsborough/central Pasco County home sales rose 9 percent, from 1,216 in February 2009 to 1,325 in February 2010. Average sales price dipped 3.2 percent, from $158,036 to $152,991. Springtime could be telling for the Tampa Bay housing market. Home prices have pretty much stabilized since last spring, but two threats hover on the horizon: The home buyer tax credit expires April 30, and the Federal Reserve is withdrawing financial props that have kept mortgage rates at record lows.