If you upgrade Spotify for Linux to 0.8.8.x version and you have some network connection problems (for example you're behind a company firewall and need to set a proxy...) the application will crash/hang without letting you doing anything (neither setting Proxy informations)
This is caused by a deadlock in the GUI and you can view the complete
debugging informations here http://pastebin.com/zcKgXEqz
To fix this, you just need to open this file \~/.config/spotify/prefs and add these two lines:
of course substituting 126.96.36.199:1234 with your proxyip:proxyport.