Its probably because there is an error or that you forgot something in the process. Here is a little "step by step" reminder about the validation of your blog:
1 - Create a new post in your blog
2 - Insert the Boosterblog logo in this very same post
3 - Add a link straight to the Boosterblog homepage (it should look like this: http://www.boosterblog.com)
4 - In the confirmation page, insert the page of your blog where we can find the post we mentioned previously. (example: /3.html)
Warning: If your post is on the homepage (first page) of your blog, you shouldn't mention any page, just leave it blank and confirm.
If you think you did it right, then it must be one of the 4 following reasons:
1 - Error in the URL
Maybe you wrote it the wrong way during the registration process, in this case, you have to delete it and add a new one, be careful this time!!
2 - You forgot the slash
When confirming, when you enter the page of your blog where the http://www.boosterblog.com is located, maybe you forgot the slash / which is before the page number. (eg.: /12.html)
3 - Wrong typing
When confirming, when you submit the page where the link to http://www.boosterblog.com is.
You maybe typed it wrong.
For example, instead of "/xx.html" you typed "/xx.htlm".
4 - Global Error
You don't recognize your problem in any case we mentioned above, and it still doesn't work ...
Then it's maybe the link you've added which is not functional (you cant click on it, or maybe its an error in the website URL ...)