I also got this problem.
Today after I restored an image of my system (doesn't matter why), the McAfee software said it's not updated, I try both McAfee updating on its own (usually works), the 'fix' and the 'manual update'. It downloads, then starts installing, and then suddenly comes to a stop, without really updating anything.
I 've tried removing temporary files, restoring the image again etc., I got the same result.
Later attempts produced some kind of updating error, stating that I need to reinstall VirusscanPlus ! (too much effort, I don't use default settings and do use other security software)
Someone in this thread suggested removing the DAT folder. I did that (I'm not quite sure what exactly I removed!), and now it seems I'm OK. I have today's DAT.
BUT: some time ago, I was auto-updated from SecurityCenter 9.0 to 9.3, same for the firewall, virusscan. Later I restored an image, it updated to the correct DAT, but the SecurityCenter stayed at 9.0, same for virusscan and the firewall.
Now again, I'm at version 9.0.
This reminds me about something that happened a couple of years ago when I could not update the DAT and had to figure out on my own that I needed to update the engine (SUPERDAT?) first.
These problems should not occur.