There is also a button combination on the ZaggMate keyboard for the same purpose.
Hold down the Control key and hit F3 - it will immediately pop the on-screen keyboard up. However, rather than disconnecting the BT keyboard, it just pops up the on-screen one. The BT keyboard still remains active and useable.
Found this thread while searching for my still unanswered problem. See i use a keyboard a lot with my iPad. Often i go in to a meeting where my keayboards bluetooth (lying on my office desktop) still is connected. I would lilke to press the eject button on the iPad. I stead of having to turn of the bluetooth. Same problem, lying on coach or bed etc. Are there anyway to do that or do you have to have the keyboard?
Sorry, but my,experience with a Bluetooth keyboard (the Apple one) shows me that you'll have to turn off the Bluetooth on the iPad when the keyboard is not available to "give" keyboard input back to the iPad. As far as I can tell, if you don't push the button on the keyboard, that's the only way to disconnect the two.
P.S. While I couldn't help you in this regard - let me take the opportunity to welcome you to the forum. It's good to "see" you and I hope you enjoy your visits.