I did a quick google search, and found this reference to khubd:
http://lists.ssc.com/pipermail/linux...il/008435.html
which seems to indicate that it is a kernel process associated with USB devices.
I did a grep of my kernel sources, and found references to khubd in all the kernel sources that I have (2.4.18, 2.4.26, 2.6.6) and there is a bit about khubd in the Doccumentation in your kernel source tree in ./Documentation/usb/hotplug.txt
Hope this helps
jacks4u