Dual VNH2SP30 MD03A with Arduino, speed control and PWM

Hi all,
I have been working with you guys for some time now, really happy with your product:s)
There is a problem I have been having with controlling the speed of my motors by controlling the output voltage determined by the PWM signal.
I can control the direction well, the mototrs are working fine when the PWM is set to full(255).
BUT once I try to lower the volatge, the stangest thing happens!
Every time I set the value of the PWM to anything higher than 127 (50%) the output volatge is the max (12V in my case) and every time I set the value of the PWM pin to anything lower the 127, I get the same volatage all the time! (2.37 V, very low which is not enough for my motors to even run…)
Any help will be much appreciated!
Best Regards

Hello, noamk.

Can you post more details about your setup? What Arduino are you using and are you sure the pin you are using is capable of a PWM output? Could you post a simplified version of your code that demonstrates the problem? Additionally, can you post pictures of your setup that show all of your connections?