Since late 2008, I have been running a 2.2GHz / 3,1 / 4GB MacBook, now at 10.5.8. A few days ago I bought a 2.66 GHz / 1,1 / 6GB Mac Pro, now at 10.7.5. I can not seem to get the Lion Mac Pro to successfully receive a 3.3mb file sent, via BLUETOOTH, from the Leopard Macbook. Sending the file, from the Leopard MacBook, usually, fails and gives the message, "There was an error connecting to the device". A few times I did get an incoming file alert on the Mac Pro and the file seemed to begin coming from the MacBook; however, the estimated time varied wildly and the file transfer eventually failed and displayed the aforementioned message. I have an android 2.3.6 phone and I was able to successfully send the same 3.3mb file to the Mac Pro in a matter of a minute, or so. I may downgrade the Mac Pro to 10.5.8, because I have important software/hardware that may not be supported on Lion, but, right now, I am trying to determine compatibility with my important Leopard software/hardware. For the time being, I want to send files to the Mac Pro via BLUETOOTH, as opposed to any other transfer method.