The process of replacing the file takes some time because it is a technically complex process. Whether on Slideshare or on a blog embed, you should wait for at least 30 minutes for the changes to reflect. If even after 30 minutes you are unable to see the updated file, please clear your browser's cache and try again.

Also if you are continuing to see the old file, try opening the presentation URL in a new browser (sometimes the browser cache causes the old file to appear for sometime, even though the replacement was successful).

If this still did not help, please file a ticket.