Pixie4 Controller not recognized by HW Utility but works fine in Sequence editor

[Achint Mehta]

I have a Pixie4 controller that was working fine until yesterday. I was able to download a standalone sequence (duration 1 minute, size 93 bytes) to it. 

The Pixie4 controller was being used as master controller for CMB24D slave controller. 
When these controllers are connected together in standalone mode, they are working fine and play the sequence as expected.

But when I disconnect them and connect the Pixie4 controller to the computer, the Hardware utility seems to be having hard time detecting the controller. Sometime the RED status LED does not turn solid and keeps blinking. 
However, if I launch the Sequence editor and play the sequence the Pixie4 controller works fine and plays the sequence. 

I have tried rebooting the computer. Also verified the Max unit Id range (set to 1E) is above the Pixie4's unit id (0A, 0B, 0C, 0D.)

Any ideas on how to debug this issue?