power toggle puzzle

Maybe (probably!) some of you are more clever than I am.

Last night I assembled a system from components; I will list all components at the end of this post but I think that the relevent pieces are:

*Intel BOXDX38BT LGA 775 Intel X38 ATX DDR3 Intel Motherboard - Retail
*APEVIA MX-Pider MX-PIDER-NW-BK/500 (Full Tower, 500W Power Supply)

I hooked all components up properly; I made sure all three power cables (4-pin, 4x2, and 12x2) were connected to the motherboard. After plugging in the power supply an indicator LED lit up on the motherboard next to the 12x2 socket. I take this to mean that the motherboard is receiving power.

Problem: the case power switch does not work. I can press the power button as many times as I'd like to no effect. Here's what I've tried:

1. Playing with the connectors for the front of the case, especially the power switch leads;
2. Plugging and unplugging power connectors for various components;
3. Hooking up the power toggle from another case to the new motherboard

None of these things has had any effect. Ideas about what could be causing this and how to fix it?

Thank you kindly. A full list of components:

Motherboard: Intel BOXDX38BT
Case: APEVIA MX-Pider MX-PIDER-NW-BK/500
CPU: Intel Core 2 Duo E8400
CPU HS/Fan: ARCTIC COOLING Freezer 7 Pro
Video: EVGA 01G-P3-N870-AR GeForce 9600 GT
HDD: Western Digital Caviar SE16 WD6400AAKS 640GB
DVD: SAMSUNG Model SH-S223Q/BEBN
RAM: Patriot 4GB (2 x 2GB) 240-Pin DDR3 1333 (PDC34G1333LLK)