Oil light in 1999 Plymouth Neon flashing on/off?

My Neon's oil was just changed.. it has 180,000 miles, and runs well.. but after the oil change yesterday, the light is still coming on while the car is running. Should I have a factory brand filter put on, instead of a FRAM (walmart brand) filter? Might this be the problem? I will post more info if it is requested by answerers. :)