I have problems controlling/adjusting monitor parameters (brightness, contrast, color etc.) in Linux, with software tools like DDCcontrol.

Buttonless LCD monitors like Samsung 173P, 193P are controlled through their software (MagicTune) to adjust parameters like brightness, contrast, color etc. This is done using DDC/CI protocol.
The big problem: this software is supported only under Windows. An alternative under Linux is DDCcontrol.

Iíve tested DDCcontrol with Samsung 193Pplus and RIVA TNT, under Fedora Core4 (P3, VIA chipset). Everything worked flawlessly.

Now Iím trying to use DDCcontrol with the same Samsung 193Pplus and ATI Radeon 9250 AGP8x/4x, on another computer (Compaq Deskpro EN, Pentium 3, Intel 815 chipset, AGP4x) with MSI ATI Radeon 9250 but it seems it doesnít function.

DDCcontrol is using direct PCI memory access for Nvidia and i2c-dev for ATI (details here)
I think the problem is with i2c-dev or with the framebuffer driver for ATI.
I receive no answer after:
#modprobe i2c-dev
How can I check if itís everything OK with i2c-dev and with the framebuffer for ATI under Fedora Core4?

I need your help to solve this problem.
Thank you.