STR troubleshooting

Microsoft Windows

I have been unsuccessful in getting my system to an S3 state. The
motherboard, an Asus P4S800, has STR enabled in the BIOS, however when
entering the "Standby" state in MCE, the molex connectors remain fully
powered- something I understand would not be happening if I were actually in
S3, and indicating I am likely still entering S1.

Firstly, are the molex connectors powered off in an S3 state?

Secondly, assuming the answer to the above is yes, what steps can I take to
determine why my system is entering S1 instead of S3?

Thirdly, how can I positively verify what Standby state (S1, S2, or S3) I am
entering?
NOTE: ACPI Suspend-to-RAM was *not* activated at the time I installed MCE.
Is it possible I need to run a repair install to alter the current ACPI
setting?