fsuwolf and soybean...
I am in agreement when you state that others are having this issue with WGA validation, however, the problem usually occurs when someone is using Windows software on more than one computer...or a product code that has already been validated.
Most of the time on a "clean" install...from a Windows XP cd (that is not OEM) you will get the prompt for validation. If Windows cannot validate, you'll be given the option to call for validation...where you'll be asked if it is a retail or OEM version and the reason why you are having issues with validation. If the reason is acceptable, Microsoft will give you a validation code to enter at the validation prompt.
The problem is that OEM software is usually proprietary for a particular machine and you cannot install it on a different machine. For instance...installing from a Dell recovery cd on a Gateway machine.
A Windows XP retail cd can be installed on any PC, but can only be registered and validated once...unless you need to reinstall the software, in which case you'll need to go through the validation process I described above. Microsoft will give you a validation code to enter, if the procedure is followed correctly during the install. This usually resolves the issue you seem to be facing fsuwolf.
Please go to the following page for more FAQs and info on Windows Genuine Advantage validation:
http://www.microsoft.com/genuine/downloads/FAQ.aspx?displaylang=enHope you find this info helpful and not redundant.