Sure sign of a long standing code base. I have been living in one code base for 10 years now and shudder at some of the older code now.

I refactor when I need to touch areas to clean up this sort of thing :)

The other mistake I see a lot in code done around the time of C# 3.5 is misunderstanding of what is lazy and what it not. Real source of subtle bugs. Worst is mutation of stuff in a lazy evaluation.