volume pedal help

[become2@fast.net]

I just got a used ernie ball volume pedal--my first volume pedal--and find it produces a very slight, gradual increase until the last 1/2" of travel, when it suddenly goes through the entire usable range--as if it's logarithmic rather than linear.  I'm finding it hard to use effectively for anything but full on-full off shifts, when what I want is the ability to modulate volume more subtly.  So my question:  is this normal?  Do I just need to work on my technique, or is there something I'm missing?  another pedal that might work better for my needs? 

thanks for any and all help--

Bruce Comens