I have the same problem. Also on a Samsung Galaxy Note.
No other devices connected.
On Calibre installation, the welcome guide asked me about my device, which is kind of weird... maybe I don't have a device? Maybe I'm just planning on using the content server? Anyway, I had to tell it something so I entered the "Android" device. Dunno if that matters.
Moving on. I do not connect my phone to the computer via cable at all. But when connecting wirelessly I get that message.. "The connection failed because some other device is currently connected to calibre...." which is weird in itself. I mean, it's 2012... we have multithreading and multiple network connections... If the message was "There is already 500 devices connected, you'll have to wait!" I'd understand.. but "some other device" ?? Come on...
Oh, I've tried that debug device detection thingy in Calibre but it seems to lock up, I'm not getting anything.