Yes I'm using it right now. Are you talking SiteAdvisor or SiteAdvisor Plus?
Best always to download from with
http://www.siteadvisor.com or from your online account which is created whenever you register a McAfee product.
If it is acting up then uninstall it in the normal manner from Control Panel/Add or Remove and reinstall after a reboot.
I can't answer for accounts, you would have to speak to Customer Service, top of page second from the left.
Blank images are usually caused by IE8, are you using it? What version of IE do you have installed? All McAfee products rely on IE for display as they use HTML.
Either that or your Windows is missing something. Check for all updates, both critical and non-critical using Microsoft Update rather than Windows Update which is the older version.