Programming Arduino wirelessly via XBee

Unfortunately you may need an oscilloscope to check the reset line.
You won't catch an oscillation with the LED. You shouldn't be getting
an oscillation but it would nice to see how clean that line is.

The only other thing I can think of is the version of the bootloader. Are you using
the bootloader version that ladyada recommends for this particular application?

(* jcl *)