I am using a 2.6.24 kernel on an ARM based board and I had a strange problem:
ping was neither working on my wifi dongle , nor on my USB-to-Eth adapter.
I used wireshark to look at what was happening on the network and I noticed that packets were sent from the board to my PC, and that my PC was replying, but the board was only getting 1 of every 10 packets.

While investigating, I noticed that those network adapters started working when I was mounting the usb FS, but only if the driver was loaded AFTER I mounted the usb fs.
mounting the usb filesystem is done with the foloowing command:
mount -t usbfs usbfs /proc/bus/usb/

So the problem is fixed for me and I hope this post will help someone!