I encountered this problem when I wanted to embed Google Presentation in Wordpress post. So as usual, in writing post screen, I switch to ‘HTML’ mode, paste the code and go back to ‘Visual’ mode. Surprisingly nothing showed up, so I switched back to ‘HTML’ mode, and found out that the embedded code is no longer there. Tried couple of times but with no luck.

I headed to Wordpress forum, and moments later found what the problem is. This is a known issue in Wordpress 2.5 and above. Whenever ‘iframe‘ code is copied to the post on the ‘html’ mode and when you switch back to ‘Visual’ mode, the code will be gone. The milestone for this bug to get fixed is on 2.9.

The workaround is, once you had put the code there, don’t move back to ‘Visual’ mode. Directly save or publish the post, and the embedded code is viewable. So whenever you want to use ‘iframe’ code in your post, make sure you have finished writing your post, and embedding this code should be the last step before you publish the post.

Alternatively, you can also stay in HTML code whenever you edit the post. Enjoy the slide!