Hi,
In v3.95 with hotfixes, if you have "Add To Cart Requires Login" selected, it does bring up the login screen when you add to the cart via the product list page. But if you click Add to Cart on the product details page, the login screen is not displayed.
This may or may have something to do with the following Javascript error in Internet Explorer. On the Product Details page, in IE8, I see this error when viewing a product (this error also appears on the www7 test site):
Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; GTB6.6; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 3.5.30729; .NET CLR 3.0.30729)
Timestamp: Thu, 9 Dec 2010 16:08:45 UTC
Message: Object doesn't support this property or method
Line: 172
Char: 9
Code: 0