WGA has two incarnations that I know of. The first is the basic proof to M$ that you do indeed have a valid windows. It periodically updates components of itself, and a recent update, maybe a month or two ago was considered outside the rules, because of the way it updated with no notification, in the background.
The other beastie is WGAnotify, a tool M$ have so generously made available to let the users know when they might be running a pirated windows. And there are lots of stories about this one getting it wrong. Keef, I suspect it is this one that has caused you problems.
There has been widespread condemnation about this WGA Notify. To the extent that there has even been a third party tool released to remove it. (Worked, too. I don't want spyware on my computer, no matter who the author is, and especially if it's faulty. The spyware, that is.)
More info here. (Use at your own risk.)
(Maybe this is to do with the reg entry you recently changed on the laptop, in your other recent post?)
[Edit] PS, just to make it clear, I have no problem paying for a genuine Windows, and have done. I won't use pirated software. I do have a problem when M$ starts to treat its genuine customers as thieves.