The most common reason for this is bookmarking code from this site - http://www.addthis.com/ has been added to the site.
Either update the code to the latest version or you can place a condition around the code that ensures it does not display on the PSP Bounce page.
If you wish to apply a condition to the code, go to the 'addthis' script code, and paste the following just before it: -
<actinic:block if="%3cactinic%3avariable%20name%3d%22PageType%22%20%2f%3e%20%21%3d%20%22PSP%20Bounce%20Page%22">
and this code just after it: -
</actinic:block>
and click 'OK'.
Once you have uploaded the changes will take place and users of IE7 will bounce correctly.
Either update the code to the latest version or you can place a condition around the code that ensures it does not display on the PSP Bounce page.
If you wish to apply a condition to the code, go to the 'addthis' script code, and paste the following just before it: -
<actinic:block if="%3cactinic%3avariable%20name%3d%22PageType%22%20%2f%3e%20%21%3d%20%22PSP%20Bounce%20Page%22">
and this code just after it: -
</actinic:block>
and click 'OK'.
Once you have uploaded the changes will take place and users of IE7 will bounce correctly.