Actually, I find the opposite to be the case--static typing helps me use unknown libraries. The types immediately let me know exactly what a function expects and what I should expect from a function. They also prevent me from using things incorrectly most of the time.

Essentially, the types are compiler-enforced documentation. They also make discovering functions easier--a type is a succinct summary of what a function does, so I can just browse by types to find what I want quickly. Augment this with great tooling like Hoogle (a type search engine) and you've got a truly awesome development system.