Again usb fails to enumerate

 Again usb fails to enumerate

hai,

Earlier I had problems with FX2 enumeration. But when I changed the port it was working well.
I have developed the firmware for one board with FX2. Now I want to use the same firmware for another board which is purchased commercially. I had some problems with fx2 enumeration some times .When I changed the port it was ok. But now Iam facing the same problem. Everything is working fine for my first board even now . iam using the same PC,same firmware ,same fx2 device . How is that it works fine for one device and it fails for one device?

I tried to find things using USB trace . In the failures there is no device start and in the sucess there is device start. That is the information i could get from it .

Any help?
Thanks in advance
punitha