There is a hash in the URL of the link, and the Forums wreck the URL by parsing it as Twitter traffic. Oddly, this only happens after the post is published, the links work as expected when previewing a post.
My suggestion would be to disable Twitter parsing for text within href or code tags.
Thank you for drawing this to our attention Andrew. I believe the hash tags should work correctly still but not be triggered in these URLs. Please feel free to let me know if you see further examples that need attention.