Is there a good way to improve the functionality and reliability of
USB hubs on PCs?  I have several hubs, all of which have external
power sources.  Still, they when I plug devices into the ports on
these hubs, they often are not recognized with the same degree of
reliability as with a built-in port in the computer.  Do you have any
suggestions as to how I might improve their performance?

Some of the old USB 1.1 and pre 1.1 device have compatibility issue,
which makes hub and device sometime not recognizing each other.