I got a PC, wich has a motherboard with a SIS671 integrated videocard, until here there's no problem because ROSA include the driver; but I also have got a Samsung Sync Master 943nwx wide monitor, and I want to set it up in a 1440x900 resolution. When I do it as "Flat Panel 1440x900", the screen becomes black... that's why I think it could be a problem with monitor frequency.
The monitor syncronization is: horizontal 30 - 81khz, and vertical 56 - 75khz. The optimun resolution is 1440x900@60hz and maximum res. 1440x900@75hz.
This is the modes table:
Display mode horizontal freq vertical freq pixel clock sync polarity
vesa 1152x864 67.500 75.000 108.000 +/+
vesa 1280x800 49.702 59.810 83.500 +/+
vesa 1440x900 55.935 59.887 106.500 -/+
vesa 1440x900 70.635 74.984 136.750 -/+
I really apreciate your help, and sorry for my little english

Greetings from Argentina.
Long life and prosper!