I'have the same problem and is a week that i can't solve it.
I have libusb but when i tipe "cd /var" i get "/tmp#" is this the problem?
i'm running fowsr 1.0-20110904-1 on OpenWRT, all usb driver are all well installed....
The files wunderground.sh and fowsr.sh (and others) contained "^M" char on each end of line that i remove but it still doesn't work giving me this result:
root@OpenWrt:/# fowsr -w
00414764 | 4F F5 43 2D __ __ __ __ __ __ __ __ __ __ __ __ | OõC-
usb_set_debug: Setting debugging level to 255 (on)
usb_os_find_busses: Found 001
usb_os_find_busses: Skipping non bus directory devices
usb_os_find_devices: Found 002 on 001
skipped 1 class/vendor specific interface descriptors
usb_os_find_devices: Found 001 on 001
error obtaining child information: Inappropriate ioctl for device
USB error: could not get bound driver: No data available
usb_get_driver_np returned -61
00414760 | 4F F5 43 3F __ __ __ __ __ __ __ __ __ __ __ __ | OõC?
failed to release interface: 0
failed to close interface: 0
If i type "vi /var/wunderground.sh" i get an empty file.
HHHHHHHHHHHHEEEEEEEEEEEEEEEEEELLLLLLLLLLLLLPPPPPPPPPPPPPP!!! :-(