Description of problem:
Parole 0.5.1 crashes on start if the "remember playlist" setting is activated.

How reproducible:
allways

Steps to Reproduce:
1. Open parole settings
2. Activate the "remember playlist" setting
3. restart parole

Actual results:
Parole crashes on start

Expected results:
Parole should start normaly and load the last playlist

Additional info:
Deactivating the "remember playlist" setting by using Xfce's settings editor is a suitable workaround.