This sounds like you computer is having trouble keeping up. What are your computer specs - OS? RAM? CPU speed?
First off, try playing with the buffer size (see Line 6 Audio-MIDI Devices control panel). Also try turning off all other programs - even disconnect from the Internet and turn off your virus/malware software.
You sure about that, when i connected X3Live it runs smoothly ...
I tried your advices... but it still works fine after launching Aantivrus, connecting netcable.... strange...
thx help anyway....