bar code printed with HP Laserjet 4100

Hi,

i have created a bar code in SE73 (type Code 39). If i print something using this bar code with printer HP Laserjet 4100, scanning device does not recognize the bar code.

If i print same bar code with another printer (Xerox WorkCentre 3210) , the bar code is recognized by scanning device.

What's wrong? Why HP printer does not print recognizable bar code?

Thanks in advance.