This kind of problem might appear with old, outdated soundcards. Modern audio systems like the M-Audio Delta Series are not affected. If you are experiencing this kind of problem, make sure to install the most recent driver for your Mainboard’s Chipset (e.g. Intel, VIA SiS). Some mainboards also require a driver update for the onboard USB host controller. Most USB-host and PCI-bridge problems can be fixed by updating these drivers. You can find the Chipset and USB driver updates on the mainboard manufacturer’s web site. If you are using USB 2.0 ports with Windows XP, you additionally have to make sure to install Service Pack 1 for Windows XP.