Ok, this is my directory listing:

#/usr/src/acx-20080210/
-rw-r--r-- 1 huub users 22374 2008-02-10 21:06 Changelog
-rw-r--r-- 1 huub users 2120 2008-02-10 21:06 Kconfig
-rw-r--r-- 1 huub users 621 2008-05-03 21:16 Makefile
-rw-r--r-- 1 huub users 5256 2008-02-10 21:06 README
-rw-r--r-- 1 huub users 140 2008-02-10 21:06 acx.h
-rw-r--r-- 1 root root 150764 2008-05-09 22:36 acx.o
-rw-r--r-- 1 huub users 1432 2008-05-03 21:15 acx_config.h
-rw-r--r-- 1 huub users 20018 2008-02-10 21:06 acx_func.h
-rw-r--r-- 1 huub users 69728 2008-02-10 21:06 acx_struct.h
-rw-r--r-- 1 root root 8 2008-05-09 22:35 built-in.o
-rw-r--r-- 1 huub users 195669 2008-02-10 21:06 common.c
-rw-r--r-- 1 root root 77568 2008-05-09 22:36 common.o
-rw-r--r-- 1 huub users 14642 2008-02-10 21:06 conv.c
-rw-r--r-- 1 root root 5300 2008-05-09 22:36 conv.o
-rw-r--r-- 1 huub users 66584 2008-02-10 21:06 ioctl.c
-rw-r--r-- 1 root root 28076 2008-05-09 22:36 ioctl.o
-rw-r--r-- 1 huub users 127472 2008-02-10 21:06 pci.c
-rw-r--r-- 1 root root 44524 2008-05-09 22:36 pci.o
drwxr-xr-x 2 huub users 4096 2008-02-10 21:12 pktgen
drwxr-xr-x 3 huub users 4096 2008-02-10 21:12 script
-rw-r--r-- 1 huub users 4533 2008-02-10 21:06 setrate.c
-rw-r--r-- 1 huub users 52695 2008-02-10 21:06 usb.c
-rw-r--r-- 1 huub users 11516 2008-02-10 21:06 wlan.c
-rw-r--r-- 1 root root 2776 2008-05-09 22:35 wlan.o
-rw-r--r-- 1 huub users 8556 2008-02-10 21:06 wlan_compat.h
-rw-r--r-- 1 huub users 15883 2008-02-10 21:06 wlan_hdr.h
-rw-r--r-- 1 huub users 17303 2008-02-10 21:06 wlan_mgmt.h

Looks to me like Makefile actually is there. But this line looks odd to me:

scripts/Makefile.build:17: /usr/src/acx-20080210/acx/Makefile: No such
file or directory

There is a directory "script", not "scripts". Any clue about that?