Users of TinyMCE 3.4.1 and below should update to TinyMCE 3.4.2 to fix a number of compatibility issues with Internet Explorer.

I’ve noticed that TinyMCE 3.4.1 breaks in Internet Explorer 7 and Internet Explorer 8 with any pages with content using CSS float. For instance, if you have floating left or right DIVs on a page, the content won’t be selectable.

TinyMCE 3.4.2:
http://tinymce.moxiecode.com/download/download.php

Downgrading Internet Explorer from 9 to 8 is a feature “hidden” from view in Windows 7. Since there isn’t a download available for Internet Explorer 8 in Windows 7, the only way to revert back is through the “View Installed Updates” menu inside Control Panel -> Programs.

I had to revert back to IE8 since we still have a number of users with Windows XP (which only runs in IE8)

You can remove IE9 and install IE8 using the following steps.

1. Close all programs.

2. Click Start, and then click Control Panel.

3. …

The cache in Internet Explorer is not very AJAX friendly for GET/POST commands. You must put in a constantly changing variable in the URL such as date with seconds in Internet Explorer. I noticed this when the refresh of my GET command would only work once in my window.setInterval(.. , .. ) function.  However, in Mozilla and Safari, my function was working perfect.

The solution to this is to append the current date and time into the URL of your GET/POST request. Special thanks to this post.

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I previously tried setting the cache to expire on the PHP header …