Problem using L298

Hello,

I am trying to use the L298 Motor Driver to control a small 12v pump. I am using the FEZ Raptor, with the 4.3 drivers. If I use a value of 1 for SetSpeed, it runs, but anything less than 1 it does not run. I see the note about setting the Frequency, however how do you have any idea what frequency to use? This is the pump I am using:

Specifications:
Sizes and weight:51x34x42.7; 50g
Driving method:Brushless, Permanent Magnetic , 2 phase
Pump material:ABS
Condition of use: Continuously
Fluids: Water, oil, gasoline, acid and alkali solution
Max working temp: 60 Celsius
Power consumption: 4.2W
Rated voltage: 12V DC
Voltage used: 12V dc
Max rated current: 350mA
Max flow rate: 4L/MIN(1.06G/MIN)
Max Static Head: 3m(9.7ft)
Noise: <40dB(most 35dB) Life span: More than 30000hrs

Thank you very much for any suggestions.

@ CodeGreen - Do you get the same result if you try to go backwards, i.e. -1 for speed? Can you verify that the board is still outputting a signal for values less than 1? As for frequency, it will be motor specific. Most motors will work fine with the default.