Did you make or bought the power cables from PSU to the HUB's? I'm also using one of those 10 ports HUB (with 9 USB Gizmos), with a Velleman multivolt, that gives 7,5 Amperes @ 5 volts.
Originally I ordered some 2.1mm connectors but they haven't arrived, being impatient I cut the 5V lines out of the molex connectors of the atx psu (bottom of pic) and soldered the 5V wires straight to the hub.. and plugged the fans into the molex (which now only has 12V lines).
ATX PSU has 28A @ 5V 4X 20A @ 12V (Reserved for K16`s)