I have this problem as well. I purchased Mcafee internet security 2009 a couple of weeks before and decided to install it today. I got the blank security screen. I ran that virtual program and there was nothing wrong. So I don't know what to do. Conflicker worm is scarying me.
If the security center is a blank page, then how am I supposed to do a scan and get updates and stuff. When I try to access the tech support chat thing, the chat pop up box comes up then it freezes and says not responding.
firefox. I am starting to think that I have some type of malicious software on my computer because my computer is running very slowly. It is kind of coincidental that after I installed Mcafee my computer started running slow.
Did you try resetting IE as per post #10? It's important even though you use Firefox as McAfee's interface uses HTML and relies on a working, up-to-date IE to function properly. So it's very important that your system is totally up to date.
Try the free versions of both of these tools and let them clean everything they find: