[ODE] Angular motor weirdness

[John]

Howdy!

I've got a question regarding angular motors.  I apologize if this 
question is answered in the docs (if it is, I haven't been able to find it).

I've got this mass (1 unit) chillin' with an angular motor attached to 
it.  I give it an axis and a maximum force (say 2 units).  Then I tell 
it to achieve a velocity of maybe .5 units (dJointSetAMotorParam(jointX, 
dParamVel, .5)).  Everything seems to be all hunky-dory, but after a few 
seconds I notice that the mass is spinning way too fast -- it actually 
seems to be constantly accelerating.  But dBodyGetAngularVel(bodyID) 
tells me that it's going .5 units/sec, even when it's obviously still 
accelerating.  If I tell the motor to stop by setting its target 
velocity to zero, it almost instantly complies.  When I start it back up 
again, it's back up to its much-too-fast rotating again with not nearly 
as much ramp up time.  Anyone know what's going on?

Thanks much!

-- John