Windows PID has expired

I purchased a W7 professional upgrade DVD from MS. Did a clean install and activated it. Windows activation shows that my version is activated.
I wanted to start a support call on the MS support web-site. One step is to provide my Windows PID what I did, but I got a message that my PID has expired.
How can that be but still show activated?
With the W7 updates I had also installed the "check for genuine version", ran it and got a confirmation that i have a genuine W7 version.
So what do I need to do to have an valid PID?

Call MS tech support and they will sort it out for you. You could be typing in an incorrect character, or there is a flaw in the system.

When you speak with MS, if asked tell them you had the old qualifying XP or Vista (you have one, right?) on the HD at the time you clean installed with Upgrade version or they may send you back to do it over again. (Been happenin lately, for some reason - which is ironic since they were giving out the registry workaround in Oct.)

Thanks for your reply. And yes, i have a legit copy of Vista Business (came preloaded on my Thinkpad).

Spoke to tech support and what that "PID expired" means is that the 90-warranty for the new product is over, which in my case is correct. MS certainly could have made the message more obvious that it relates to warranty and not activation.

Saltgrass was mentioning some signs that they might be tightening Upgrade version clean install restrictions.

Have read speculation all along that that might happen once all the beta testers got Upgrade version installed with workaround.

Of course, the Vista workaround (upgrade over itself) lasts to this day for Vista (and now with Win7) so there's probably no worries they will require qualifying OS key since they didn't for Vista.

But it's still important to keep qualifying OS key readable for the life of Win7 upgrade version.

Ummm, a PID is not the same as a product key...