Same here, I'll find myself working weekends when I just get started, and leaving early when I'm nearing the end... tricky to change since I'm just not all that interested by the end.
This is actually pretty relevant to me too. I have software trading in real time, while at the same time I'm developing new software. Every time a fill comes in I evaluate it and am always half-paranoid that I'll discover a bug in why I traded that. Makes it hard for me to focus fully on programming.