Your quesses are as good as mine, I don't have Minolta neither Alpha to test them, so I just added that Minolta remote (which was said that it may work with Alpha), crossed my fingers and kicked it to the autobuilder, because that is all I can do for cameras not made by Olympus.

Anyway, here is short check list to find plausible errors:
1. Does the IR sensor blink (just watch it trought the live view), if not, then the problem is in device (my sensor is blinking), or if you have irreco installed, it might cause some errors for lirc files.
2. If you run the pykake from the xterm (python /opt/pykake/pykake.py), do you get any error output?
3. Double check that you have set your camera in Remote mode, so it knows to look out for IR signal.