same linux installation, different font rendering

[Giacomo]

Hi to all.
I am Giacomo S. from Elettra synchrotron radiation facility, Trieste, Italy.

We use to develop Qt GUIs on a kubuntu system.

The development process is as follows:

1. develop the application on machine A;

2. install the application on machine B, where it has to be run.

Machine A and B have been installed from the same installation CD:

-> same X environment/libraries
-> same nvidia X driver (official NVIDIA, to support multi screen)
-> same qt libraries
-> same compiler/libc libc++...
...

The problem is that launching the same panel on machine B shows a different 
font rendering with respect to machine A, producing unwanted changes in the 
global layout of the graphical interface elements.

Although installations are made from  the same source and should be totally 
equivalent, I have to add that machine B has a 4 output video card.
Machines A and B have the same nvidia drivers installed.

Which is the way to follow to try to solve the issue?

Thanks for any suggestion.

Giacomo.