[debian-non-standard] USB-Stick not active after flashing

[Thomas Ohms]

Hi there,
I was following your instructions on
http://wpkg.org/Running_Debian_on_ASUS_WL-500G_deluxe for the same
model. After flashing I put everything on ext3 formatted USB stick but
when I connect the router the LED of my USB stick stays dark. Seems the
USB port isn't active. First I thought that I have done something wrong
with flashing and so I used the Windows recovery tool from ASUS to flash
again (which is quite comfortable), but same result. Also I've added a
boot flag to USB stick and nothing happened again.
Any idea why my USB port on the router isn't active?

Thanks and greets
Thomas