Url Redirect disables Add to Cart

[Brewhaus]

For SEO reasons we are redirecting /Default.aspx back to the domain without the /Default.aspx extension

(ie. redirecting
http://
www.
hotsaucedepot.
com/Default.aspx
to
http://
www.
hotsaucedepot.
com/).

However, when we enable that redirect you cannot add an item to your shopping cart from the home page. You can still add to the cart from any other page, but when trying to add from the homepage it simply refreshes the page without adding anything to the cart.

The issue is case sensitive- redirecting /default.aspx (lower case 'd') has no effect, but redirecting /Default.aspx (upper case 'D') causes the problem.

Does anyone have any thoughts on this?