First thing, could you give me the URL of the blog where you are trying to put the code?
That way I can look at the HTML and see what's going on.
This is the checklist of things that may be wrong:
- Is the blog a Blogger/Blogspot blog?
- Do you have a Blog Archive Widget on the page, with archive frequency monthly and archive style heirarchical? (Go to settings on the Archive.)
- Is the second code section below the blog archive widget, perhaps at the very bottom of the page?