Having similar issues. What do you mean with the last statement? MTT chip? i bought an icybox IB-ac611, didnt really solve anything.
Lots of people having issues with the U3 stability and performance by the way
USB 2 hub using two kind of chip. Single Transaction Translator(STT) and Multiple Transaction Translator (MTT). In the past i had many problem while using STT usb hub.
It's hard to know which kind of chip the vendor use because almost all of vendor didn't publish this. But some vendor willing to answer the question via email.