If it helps, i can tell you I have used about 10 different android devices and a few iOS devices with Air. The soft keyboard always pops up automatically as log as it's an input text field. What device and Air version are you using?
Is it an input text box?
do you possibly have anything above it? perhaps something else in the way of the touch event where its not actually hitting the textfield itself?
I dont know about the emulator, but I recently noticed if I am running a debug version of an app on my android phone and the debugger is not tied in, the softkeyboard does not auto pop up. Hardware keyboard events also are not working.
If the debug app is tied into the remote debugger.. it works as expected.
anway release builds work fine so i wouldnt worry about it.. although i'm sure your all set by now