The 2.6 kernel series does not use the modutils package anymore. It now uses module-init-tools as the way kernel modules are implemented has changed. One other difference is that /etc/modules.conf is not used anymore, but rather /lib/modules/modprobe.conf. It may be that you don't have module-init-tools installed, or you do but don't have the correct entries in modprobe.conf.
And just a note, unless you run devfs (which is considered obsolete in the 2.6 kernel series), any modules related to input (like mice or keyboard, joysticks, stuff in /dev/input, etc) cannot be auto-loaded, so they have to be loaded manually or at boot up in /etc/modules or similar depending on your distro of choice.
It's possible you know all this and in that case, then I don't know what else to suggest except go through trial and error by experimenting with putting entries in modprobe.conf. It took me such a long time to be able to get the alsa modules auto-loading as the entries at the alsa project site were not for the new style module loading when I was trying out 2.6.0-test5 ...