Ablton/asio help!

- need Ableton help asap.... anyone know what they are on about? It's an ASIO problem, I think - when I'm using ASIO DirectX full duplex from my internal soundcard, it's fine. As soon as I switch to my Numark DJ I/O which is listed as Numark USB audio device - all audio stops and Ableton starts running slow as ****.

Help!

sorted. for anyone running the same set up - there appears to be a known issue with on-board sound. as soon as that was disabled, it all ran happy days.