Trying to give something back to the Community...
Symptom
System Center Configuration Manager 2007 Service Pack 1 (SP1)-based systems cannot provision clients that have the AMT 2.2 or AMT 2.6 chipset in the PKI mode. The provision process fails in the SetTLSCertificateWithKeyPair() function.
Additionally, System Center Configuration Manager 2007 SP1-based systems cannot provision clients that have the AMT 2.1 or AMT 2.5 chipset in the PSK mode.
http://support.microsoft.com/default.aspx?scid=kb;en-us;959040&sd=rss&spid=12769
Read the complete post at http://wmug.co.uk/blogs/cliffs_blog/archive/2008/12/23/configmgr-system-center-configuration-manager-2007-service-pack-1-systems-cannot-provision-amt-2-2-2-6-clients-in-pki-mode-and-amt-2-1-2-5-clients-in-psk-mode.aspx