[LAU] UA25 noise problem w. nVidia chipset

Greetings, I've been working with Ardour3 on my laptop, a machine with an AMD Turion X2 CPU and an nVidia 8200M integrated video chipset. Recently I started monitoring my test recordings through the headphone output of my UA25 and I notice that when I move the mouse it creates scratchy sounds, though QJackCtl reports no xruns and my recordings are unaffected. I verified the problem with Ardour2 and Mixbus. It doesn't occur when I use the integrate audio chipset (snd-hda-intel, wahoo). Running 'cat /proc/interrupts' reports that usb1/usb3 share interrupt 17 and usb2/usb4 share interrupt 16. I've tried switching ports around but that didn't get rid of the noise. Any further suggestions ? Best, dp