I just tested the pykabe 0.7.3 (newest version). I went ahead and installed irreco so as to have the full IR package.
When I had pykabe running and tested it with my canon, nothing happened. On rare occations the lens autofocused, but nothing beyond that. So I went over the irreco and tried that, nothing. So while having both apps running I switched over to pykabe and suddenly everything worked as it should. After a little experimenting I came to the conclusion that pykabe doesn't work without having irreco running in the background.