I bought a 4-port powered USB2 hub from JayCar which worked with my QHY5 and DSLR. (The power input is 5V. There's no power supply provided.)
Before that, I had a hub I bought off eBay that didn't work - that was apparently a chipset compatibility problem.
Here's a link to the JayCar item:
http://www.jaycar.com.au/productView.asp?ID=XC4864