Looking at the code of RecordTimer.py, I can see no way that variable can ever contain either an int, or a tuple with an empty list.
So for the moment I don't think it is a bug, but caused by something that got overwritten when you installed some plugin (there are a lot of rubbish and therefore not compatible plugins out there, it is an illusion that all Enigma images are compatible).
I am also interested in the way to reproduce this problem.
o.k., let's see.
I' flashed on my STB another image for looking TV. Otherwise my PM will kill me.
Testing can be done only saturday/sunday. The better way - I need a secondary box for testing
I'll buy another one, may be a F1!