I have the same problem as Johannes. My su -c"rpm -qa | grep libusb*" result is:

libusb-0_1-4-32bit-0.1.13-14.1.2.x86_64
libusb-1_0-0-1.0.8-9.1.2.x86_64
libusb-1_0-devel-1.0.8-9.1.2.x86_64
libusb-1_0-0-32bit-1.0.8-9.1.2.x86_64
libusb-0_1-4-0.1.13-14.1.2.x86_64
libusb-1_0-devel-32bit-1.0.8-9.1.2.x86_64
libustr-1_0-1-1.0.4-20.1.6.x86_64
libusbmuxd1-1.0.7-6.4.1.x86_64
libusbmuxd1-32bit-1.0.7-6.4.1.x86_64
libustr-1_0-1-32bit-1.0.4-20.1.6.x86_64


Yet the installer still complains of: 
"error: A required dependency 'libusb (libusb - USB library)' is still missing."

My su -c"find / -name usb.h" result is:

find: `/proc/4112/net': Invalid argument
/usr/src/linux-3.1.10-1.9/drivers/usb/storage/usb.h
/usr/src/linux-3.1.10-1.9/drivers/usb/core/usb.h
/usr/src/linux-3.1.10-1.9/drivers/staging/keucr/usb.h
/usr/src/linux-3.1.10-1.9/drivers/net/wireless/rtlwifi/usb.h
/usr/src/linux-3.1.10-1.9/include/linux/usb.h
/usr/src/linux-3.1.10-1.9/arch/mips/include/asm/mach-pnx8550/usb.h
/usr/src/linux-3.1.10-1.9/arch/arm/plat-mxc/include/mach/usb.h
/usr/src/linux-3.1.10-1.9/arch/arm/mach-ux500/include/mach/usb.h
/usr/src/linux-3.1.10-1.9/arch/arm/mach-davinci/include/mach/usb.h
/usr/src/linux-3.1.10-1.9/arch/arm/plat-omap/include/plat/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/rt2x00/lib/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/orinoco/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/line6/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/wimax/i2400m/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/ft1000/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/dvb/b2c2/flexcop/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/dvb/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/libertas/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/libertas/thinfirm/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/at76c50x/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/snd/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/p54/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/prism2/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/i2c/tiny/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/can/ems/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/desktop/include/config/joystick/iforce/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/rt2x00/lib/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/orinoco/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/line6/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/wimax/i2400m/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/ft1000/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/dvb/b2c2/flexcop/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/dvb/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/libertas/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/libertas/thinfirm/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/at76c50x/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/snd/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/p54/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/prism2/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/i2c/tiny/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/can/ems/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/xen/include/config/joystick/iforce/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/rt2x00/lib/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/orinoco/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/line6/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/wimax/i2400m/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/ft1000/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/dvb/b2c2/flexcop/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/dvb/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/libertas/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/libertas/thinfirm/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/at76c50x/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/snd/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/p54/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/prism2/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/i2c/tiny/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/can/ems/usb.h
/usr/src/linux-3.1.10-1.9-obj/x86_64/default/include/config/joystick/iforce/usb.h

What to do?