Actually the code works quite well with IE. What I see happening is that you have multiple windows opening. To prevent that from happening suggest doing the following:
Change target="paypal" to target="_self". This will keep the shopping cart page on the same page. See example below:
Modify the Form target line in both your Add to Cart and View Cart Button Code.
<form target="_self" action="https://www.paypal.com/cgi-bin/webscr method="post">
The HTML command target="_self" puts the new document in the same window as the current document. Some web browsers like FireFox, Chrome and IE will open a new or second window to display a new document. In order to prevent having multiple windows open while doing a task, it's recommended to use target="_self".
** Most Important: After you have made your changes to your item button code, be sure to delete your web browser's cookies, temp files and history before testing the changes. This ensures a clean start . Delete the browser's cookies, temp files and history, then close the browser, reopen it and then test your code. Do this each time when testing, else you will experience unexpected results.
