You need to be careful and identify which port you daisy-chain from so that your devices aren't too deeply nested.  Sometimes windows has issues w/ hubs that are too deeply nested.

The RHB-500 is actually 3 separate USB controllers nested together to make a 10-port hub.

I have a Satechi hub (which will not support USB asics very well) that I used to plug in all my RHB and ebay hubs.

Are you running a bunch of bitfury or USB erupters?