Your description indicates me that html5 is not enabled/supported in both browser. You might have to disable in cq5 not to use html5.
For now in IE browser enable native XMLHTTP support and let me know how it goes. To do that check mark at
Internet Options -> Advanced -> Security (Settings) -> Enable native XMLHTTP support
Thanks for your reply.
I check my IE9 settings, I have the XMLHTTP support enabled already.
Also I have
"Disable script debugging (Internet Explorer" unchecked
"Disable script debugging (Other)" unchecked
"Display a notification about every script error" checked
When I dragged the image file to the box stating "drop an image or click to upload", both Firefox (15.0.1) and IE9 open the image file (left the CQ5 window and display the image on current window) instead of uploading to CQ5.
This problem only happened in our production server running on Linux; my local windows 7 box works fine through.
Please try  & does not work file a daycare ticket.
1. go to crx explorer
2. delete all files under /var/clientlibs
3. delete /var/classes/org/apache/jsp/libs
4. save the changes