missing symbox in es18xx - isapnp_protocol

Hi

I converted a work 2.5 config for a second processor. PNP is set as follows in .config

oscar% grep PNP .config
CONFIG_PNP=y
CONFIG_PNP_NAMES=y
CONFIG_PNP_DEBUG=y
CONFIG_ISAPNP=y
CONFIG_PNPBIOS=y
CONFIG_BLK_DEV_IDEPNP=y
# CONFIG_IP_PNP is not set

Yet I get:

*** Warning: "isapnp_protocol" [sound/isa/snd-es18xx.ko] undefined!
ld -m elf_i386 -r --format binary --oformat elf32-i386 -T arch/i386/boot/compressed/vmlinux.

The following is set for sound.

CONFIG_SND=m
CONFIG_SND_SEQUENCER=m
CONFIG_SND_OSSEMUL=y
CONFIG_SND_MIXER_OSS=m
CONFIG_SND_PCM_OSS=m
CONFIG_SND_SEQUENCER_OSS=y
CONFIG_SND_VIRMIDI=m
CONFIG_SND_ES18XX=m
CONFIG_SND_EMU10K1=m

It would seem that pnp.h exports the symbol and that es18xx.c includes this...

Ideas?
Ed Tomlinson