Failed to make buildkernel with "device ath"

I've tried to rebuild the kernel a couple of times now with "device  	ath " to 
add support for my 54g card. The system was cvsup to current yesterday ( 
29/07/03) and make buildworld completed succesfully. However rebuilding the 
kernel fails on this :

if_ath.o: In function `ath_attach':
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:198: undefined 
reference to `ath_hal_attach'
if_ath.o: In function `ath_tx_start':
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:1767: 
undefined reference to `ath_hal_computetxtime'
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:1771: 
undefined reference to `ath_hal_computetxtime'
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:1774: 
undefined reference to `ath_hal_computetxtime'
if_ath.o: In function `ath_getchannels':
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:2309: 
undefined reference to `ath_hal_init_channels'
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:2322: 
undefined reference to `ath_hal_mhz2ieee'
if_ath.o: In function `ath_attach':
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:192: undefined 
reference to `sysctl__hw_ath_children'
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:198: undefined 
reference to `sysctl__hw_ath_children'
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:205: undefined 
reference to `sysctl__hw_ath_children'
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:221: undefined 
reference to `sysctl__hw_ath_children'
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:229: undefined 
reference to `sysctl__hw_ath_children'
if_ath.o:/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/ath/if_ath.c:236: 
more undefined references to `sysctl__hw_ath_children' follow
if_ath_pci.o: In function `ath_pci_probe':
/usr/src/sys/i386/compile/DAVESSERVER/../../../dev/pci/pcivar.h:191: undefined 
reference to `ath_hal_probe'
*** Error code 1

Stop in /usr/src/sys/i386/compile/DAVESSERVER.
server#

I cant find anything similar to this in the archives and google gives me 
nothing.

let me know if any additional info is needed

Thanks 

David