I don't even see the image placeholders in my Firefox 3.0.7, but I at least see those in IE8 (final), this is in Vista SP1. However if I go to properties on each one and then display their URLs separately I can see the images....very weird.
Anyway, from what you show the first ones look normal to me - I thought that you were getting blank Security Center images.
The last one is an issue that I will have to research more. But I would imagine that McAfee was corrupted in the change from x86 to x64?
Try the following after having temporarily enabled Windows Firewall:
1. Uninstall all McAfee programs through "Add or Remove Programs" in Windows "Control Panel".
2. Use the MCPR tool, see this article:
How to remove supported McAfee consumer products using the McAfee Consumer Products Removal tool (MC... This will remove all McAfee remnants from your computer. (you must have Windows Vista, XP or 2000 SP4 to use this tool)
3. Launch Windows Explorer and delete all McAfee files in "Program Files" but especially in "C:\Document and Settings\<user>\Application Data" and "C:\Document and Settings\All Users\Application Data". You have to set Windows Explorer to show all hidden files and folders (Tools > Folder Options > View tab). Just delete the McAfee folders even if they are empty in all the "Application Data" folders. Can be more than one!
In Vista: C:\Program Files, C:\ProgramData and C:\Users\yourname\AppData\Roaming
If you can't find these files don't worry. It just means that MCPR has done its job.
4. Reboot and redownload/reinstall your McAfee products directly from your account at the McAfee web site NOT from any CD that you may have.