LOL i guss this never works because the License of XP SP3 VOL are different from XP-POSReady if you include XP-POSReady in the install CD then the system is flagged as POSReady system (inside the REG) and not as XPSP3 Vol the POSReady hack have to be installed after the license check is done on the backend system
For the record im a windows XP+posready user and my XP is OEM-SLP activated and all go well here included windows update. I make a localized posready addon with Nonofabio tool from Ryan forum
POSReady will work, but the trick is to install all the updates for Windows XP 1st, then activate POSReady and install the new updates provided.
I'm still using XP with POSReady updates, because the forum does not allow uploading of Windows Unattended, you can use Google Search "Windows XP Extend build 1711"
i think this problem can be circumvented by editing registry of the created offline image and deleting the pos key