OK, because there is an authentication on the page, I can't use my Adobe Browser Labs tool to view the site in IE 6 & 7.
I do know that on older versions of IE, you need to be very specific with your style selectors, sometimes an earlier UL or LI style might override your custom settings for .blockcontent-body.
Without being able to further analyze the site, I would suggest you do two things:
One, place an IE conditional statement in your header.php file right before the closing </head> tag.
Here is an example:
<!--[if lte IE 7]>
<style>
.blockcontent-body ul li {
}
</style>
<![endif]-->
This will allow you to play around with padding (space between element and it's border) and margins (space between outside of item's border and the elements around it).
The next thing you are going to need to get familiar with are styling the lists themselves, and the general CSS styling commands at your disposal.
I would recommend a ten minute crash course by reading through this post. It will help you get the basics down.
Good luck with your new site!