i think even u mask the es1371 in module.conf, kernel will load this module.
try to find es1371.o from /lib/modules/2.4.xx/kernel/sound/ and rename it. (do not delete it, u may need it later).
linux can not find u sound card driver by ths way. so u also need modify u /etc/module.conf, or /etc/module.d/alsa to set the sound-solt0 to the card u want to use.
in summary, u have two. a and b. u want to use a and disable b. so u need set u sound-slot-0 to snd-card-0 and alias snd-card-0 to a, not b. also set card number limit to 1. check u alsa conf file.