I have exactly this problem with about 500 Dell Optiplex 755 Clients (BIOS upgraded from A09 to A10, AMT 3.2.1) as described in the blog Entry "Intel AMT 3.2.1 Self-signed certificate issue and working around it for Microsoft System Configuration Manager SP1". Is this a bug in the Intel AMT Implementation or the Microsoft SCCM? Will this be corrected? I could correct this with a local un-provision, but the remote un-provision method doesn't work. How can i troubleshoot the WS-MAN Translator to use the remote un-provison workaround?
I think that the WS-MAN Translator doesn't work correctly, because i have also a view Dell Latitude D630c with AMT 2.6.1. This Clients could not be detect a AMT Version in SCCM.
I see someone in the vPro center answered that one.