VGA setting

Hi, I am using the SuSE 7.1 Linux with a Power Mac G3, 128 MB Ram, BootX Version 1.2b3. If I boot into the 2.2.18 Kernel the VGA mode is OK ( like I am used from the MAC side ( 1024*768). If I use the 2.4.2 Kernel ( compiled by myself or the one from the SuSE CD) the VGA mode is wrong ( 640*480). I tried to use the More Kernel argument option on BootX Version 1.2b3 "vga=extended" but there is no reaction. Does anybody have an idea how to set the video mode in the kernel? I somehow got stuck with the SAX2 programm. I dont know if this is the right aproach. Thanks for your help. Alfred Mutscheller@T-online.de