Network driver problem

[manolo]

I have an Asus A7V8X mainboard and recently installed Knoppix to my HD. It works, the only problem is that I have to compile the driver for the network card (Broadcom BCM4400 series 10/100 Mbps) and when I do it following the source tar.gz readme procedure I get the following message in the console (logged as root):

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gcc -DMODULE -D__KERNEL__ -DDBG=0 -Wall -Wstrict-prototypes -O6 -I/lib/modules/`uname -r`/build/include -c -o b44um.o b44um.c
gcc -DMODULE -D__KERNEL__ -DDBG=0 -Wall -Wstrict-prototypes -O6 -I/lib/modules/`uname -r`/build/include -c -o b44proc.o b44proc.c
gcc -DMODULE -D__KERNEL__ -DDBG=0 -Wall -Wstrict-prototypes -O6 -I/lib/modules/`uname -r`/build/include -c -o b44lm.o b44lm.c
ld -i b44um.o b44proc.o b44lm.o -o bcm4400.o
ld: no se puede abrir b44um.o: No existe el fichero o el directorio
make: *** [bcm4400.o] Error 1
************************************************** ********

Last lines translated into english:
ld: can´t open b44um.o: File or directory don´t exist
make:*........Error 1

I have no experience with Linux, and searching for help in Welsh and Kaufman's "Running Linux" didn´t help me. Any idea? Thank you.