If you take a look at this page, http://www.digi.com/wiki/developer/index.php/RCI_do_command, it shows that the extended address should end in ! for the addr attribute to work, like . Give that a try and see if it works with cache=“false”. It would be interested to know if it does work, if it still works in the case of cache=“true”.
Two years have passed since Chris gave his response. I suspect they got sick of that question and tweaked the responder to be a bit smarter and understand 8-octets as a ZigBee MAC with or without the “!”.
Still won’t hurt to follow the published rules as in other situations, the “!” will still be required. In truth, that “!” was used to allow appending end-point and cluster info to the addrees, much as a “:” is used to append port info to an IP.