I built my system from the ground up. Yes I did try each stick and they are all good and seated fully into there slots.
the specs on my system:
Motherboard - Tyan S2696 Tempest i5000XT
RAM - (8Gig in 6 Sticks 4, 1Gig and 2, 2Gig) DDR2 PC2-5300 • CL=5 • Fully Buffered • ECC • DDR2-667 • 1.8V • 128Meg x 72
processor - 2, Intel Quad-Core Xeon E5405 / 2 GHz