Simulate soapUI TestCases in Internet Explorer

If anyone can tell me off the bat if I can simulate soap UI test cases, IN IE, as well as other browsers, instead of the "mock services" area, that would be great. I am new to software testing and to become familiar with QA, as well as support it has been asked of me to test appropriate software. Our web app is in IE and I see I can "open in browser" with load UI but when I hit the URL and run a Web test case in Soap UI our web app appears broken, as it does when we run it in Firefox or Safari. Of course we are moving to cross browser compatibility but we still support and give updates to IE 150%!!! If anyone can give me a flat out answer, as I am having trouble finding this out in the forums, etc, that would be great. I am presenting my solution Friday, and so far have Sahi Pro, jMeter, and Web Server Stress Tool 2007 by Paessler! I would much rather use Soap UI and Load UI but am just stuck figuring this out today, and will have to move on to different tools if I do not get it nailed down by tomorrow. Thanks for all help it is greatly appreciated! - James Pray