Hi Antonio,
I hope you're well and not pulling your hair out in frustration just yet.
There are a few factors that you need to consider before making a decision on this:
1. Would changing the URL of the post give more traffic through the search engine than you are currently getting?
2. How would this impact the existing links that have been built to the original URL.
Remember that if you are going to change the URL of a page, this will just look like a new webpage to Google. All of the Facebook likes, Google+ +1's, links, etc will be going to the previous URL. Not only that, if you do a 301 redirect to the new URL, you will only transfer some of the link juice that you have made.
URL changes really should be a last resort and need to be thought out properly at the start of the webpage creation. In the case of Mark (above), I have recommended that he change the URLs because they are all dynamic and the benefit of changing these pages vs not, wins.
Let me know the URL of the page in question and I will take a look and tell you what I think.
Matt.