It appears we already responded to your email about this issue, but in case anyone else with a similar issue encounters this post, here was our reply:
E-junkieMonsterI'm guessing the issue is related to your page layout. Firefox handles it just fine, but when I open the site in IE it scrolls to the right indefinitely... our cart is set to open in the middle of the screen, but who knows where the middle is when IE can't even find the right edge of your page. Our cart inherits its settings from the CSS settings on your site, you might be able to use those to control the alignment of the cart and make it appear in a specific place on your page -- if that doesn't work you can remove the JavaScript we provide in the View Cart code and that should force the cart to open in a new window rather than appear on your page, that would not look as nice but it would get around this IE-specific problem.
This help page provides some other tips to resolve CSS-related cart display issues:
http://www.e-junkie.com/ej/trouble.buttons.cart-css.htm