I haven't ever experienced what is described either (in personal projects or professional work). What I find gives me "coder's block" is when I have coding tasks that need to get done, but don't really require any thinking. Tasks that are just beyond the threshold of being able to write a script to do them for you, but still feel like they are something that should be automated.

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 never have an issue with this at work. Clients give us specifications, so deciding what I need to solve is never a problem. I definitely have this issue on personal projects though. It's often because I'm still trying to figure out the problem space.

I agree with nsxwolf, this is more of a designer's block than coder's block.

I agree, and I have been a developer for much longer. Coders block? Never experienced it.

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.