[Sunhelp] Resolution

[triyono]

Hi All,
I have Ultra 10 with PGX24 and monitor 17". Right now resolution I've
check
from eeprom is : output-device:screen.

Now I want my resolution changed to 1152x900x66.76
I've done it with the command:

# eeprom output-device screen:r1152x900x66.76

but the error message : "data not available" is displayed
I've check the monitor and graphic card and they support that
resolution.
I wanna to know what should I do to solve this problem

Thank's in advance

-triyono-