As I reported, I had the same issues like you but starting from Karmic Alpha 5 onwards, the issue is gone (at least for me but I hope for all others out there, too). Kernel 2.6.31-9-generic and 2.6.31-10-generic from Ubuntu 9.10 are working just fine :-)
@ramesh: Please try a live CD of the upcoming Ubuntu release 9.10 "Karmic Koala" (you can download them here: http:// cdimage. ubuntu. com/releases/ karmic/ alpha-6/ ).
As I reported, I had the same issues like you but starting from Karmic Alpha 5 onwards, the issue is gone (at least for me but I hope for all others out there, too). Kernel 2.6.31-9-generic and 2.6.31-10-generic from Ubuntu 9.10 are working just fine :-)
Please report your results.