Is this issue common with personal projects? I've been a developer for almost ten years and never experienced it. What I do experience is the urge to procrastinate on hacker news :-)
In this case I don't think it's a block in the same sense as writer's block, but rather a block due to a lack of motivation, because such tasks aren't enjoyable in the same way coding that involves creative thinking is.
I agree with nsxwolf, this is more of a designer's block than coder's block.
Creating the solution to a problem via code is easy, finding the correct design/implementation is much harder. I tend to write code first, refactor later.