[belese]

<extension point="xbmc.service" library="default.py" start="startup|login">

this line is not good, you have to choice either startup or login, in this case, you can choose startup

<extension point="xbmc.service" library="default.py" start="startup">

don't look at the rest.
and your pyhton file must be name default.py or change it in addon.xml to correspond to your file name.
but default.py is a quite standard in xbmc.