Hi Barry,
Many thanks for your input,

I do the following test :

Launch an FTP connection at 800Ko/s (6400Kbits) which saturate my download at full speed...
and I activate in the QOS my newsgroup test which is set to min=110Kbits, max=1024Kbits

And with this I have the following result :
FTP slow down at 220Ko/s (1760Kbit...)
and my newsreader go at 4200 Kbit, 4* the max I set...

So even with an easy config I can't use a QOS...

Ulong