System not resuming from stanby mode ---Solaris10

Dear Frnds,

I have a weird issue with solaris 10.
We bought a new Sun Ultra45 workstation and i installed solaris 10 in that.
The problem is when it goes to standby mode i am not able to resume the system.The only thing i can do is to manually reboot and start working.

The problem occurs when i am in user login.
I hope this could be a power management issue.
I even tried to disable the power managemnt settings but still it didnt workout.

Is there any bug with power management in solaris10..??
Any patch available to fix this issue.???

Anyone pls help me to fix this.... :confused: