Help!! 2.5 Ton Goodman Heat Pump, when unit first turns on in cool, the suction psi is between 35-45psi, head pressure is between 125-150psi. These pressures hold steady at those psi's for 15-25 mins then both pressures slowly start rising and steady off at 70-75 low and 250-270 high depending on conditions. Problem is if pressures do not start rising fast enough sometimes unit will start freezing at evaporator. Unit does not freeze all the time just sometimes very infrequent. The air filter is clean, evaporator is clean, condensor is clean and evap. fan is running good on high speed. Could I have a restriction at the orifice, but usually the circumstances are the reverse of what i am finding. Any thoughts would be appreciated. The compressor was replaced in April 08 and has been running good up until about a week ago.