I think I've found out why it doesn't work: according to
this thread, if ADE does not recognize the keystrokes, it may be because the reader is not authorized - even though you think it is. So you have to go into 'manifest.xml' and edit the device out, and then authorize it again (see thread before doing this). Unfortunately, on Macs the device registration does not appear to go through 'manifest.xml', so the problem remains. Anyone with this problem needs to find out how OSX stores ADE device scripts. So far, I haven't found out.