Serial Buffer Overrun?

With a zigbee interface between two Arduinos controlling a simple blinking Led/Switch Combination has anyone seen a delayed blink effect. When the button is pushed with the two Arduinos wired together the light blinks immediately, but with the zigbees in line there is a 10+ second delay.

Any ideas on a solution. I've toyed with adding a delay at the sending end, but to no avail.

Do you have the zigbees running continuously? As I recall, they have some "power saving" modes, and may be renegotiating their connection after having to put themselves to sleep due to inactivity (although 10 seconds does seem awfully slow...).

Ran,
I've merged two threads that I have running at the request of Digimike.

Here's the other:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1267645563/0

And nope no sleeping for these suckers.