Hi Shunyun,
I to was getting mysterious pops and stutters when using an Alesis IO/26 on a windows partition using boot camp on my iMac intel core duo. I disabled my network settings in the control panel, restarted and everything was fine. I did have to recheck all of my settings for real tracks and real drums as they are on an external hard drive.

Hope this helps.
Bill
PS. The mac version is awesome as well. So far flawless performance.