okay...most of you have probably fixed this problem months ago...I didn't though until...yesterday...so would like to just run down the steps to make it work...
1. Tell Quicktime no. Go to system preferences -> quicktime -> plugin -> MIME settings... -> Images -> uncheck PNG image file -> hit okay
2. Switch IE file helpers to "view with browser". Explorer -> Preferences -> File Helpers ... there are maybe 3 things to change: PNG Image (image/png) PNG Image (image/x-png) and the third one is the one that I missed all these months...Portable Network Graphic (image/png). (GAAAH!!!) Give them all handling "View With Browser" and hit OK
that should do it...worked great for me