Hello
the latest kernel 2.6.40-4.fc15.x86_64 is somewhat buggy !

It does not the include module for the USB Atheros chip 9170.
As a result the TP-LINK TL-821N wireless N (very good) does not work !

The previous kernel 2.6.38.8-35.fc15.x86_64 does include them as modules.
grep AR9170 config-2.6.38.8-35.fc15.x86_64
CONFIG_AR9170_USB=m
CONFIG_AR9170_LEDS=y

Hopefully a version including those will be posted soon as an update.

Andre