PSU for GF4

I have a GeForce 4 Ti4400 made by PNY on a 300watt system and was thinking of adding one to my other system with a 250watt power supply, on thier site they say that it is required to have a 300watt. Does anyone know if this is critical or if they just say that for a "safety net" for the people that have 100 things in a low power system.

The system that I am thinking of adding it to is a P4 with 1 cd drive and 1 hdd, stock cooler and 1 case fan. 1 nic and 1 modem. Think it will handle it?

BUMP

i once had a gateway with a 200W psu that would not take a tnt2 ultra until we upgraded the psu. if PNY says it needs a 300W, i go by that. you could however, try it on the 250 and if it didn't work, replace it. 300W psu aren't that much anymore.