Reply to traktor glitching (non CPU related!!!) please help!

hi everyone

recently I have big problem with my traktor 2.5 & S4

I did find many post about CPU related glitching problem with traktor
by this one is non CPU related.

every 2-3 minutes traktor produce glitch/pop/crack sound
something similar to static electricity crack but muuuuch louder

I have HP probook, win7 64bit, 4GB RAM, i5 processor... my CPU usage is all the time at cca 15-20% max
and during that sound CPU does not jump (does not go to peek/red)
it's always at the same level

I did try to change latency, audio cable, USB port (it's 2.0, not 3.0), but the problem stays
(I can hear glitch sound in my headphones also so the problem is not in club amplifiers or speakers...)
and the problem is there with older versions also

any ideas???

thank you big time and sorry for my bad english!!