create a new folder or drag the self created "My Pictures" in my documents or desktop first
customise it for pictures then change its icon then drag and drop it in my documents
then all picture tasks should be visible again

i've dragged the default " my pictures " out of my documents into another folder on my desktop and the startbar will always link to the folder to where its been moved to.. automatically....... but i havent deleted the folder
so the answer to your question about windows having a default my pictures, the answer is yes unless we find a way to associate the new folder as a default