http://www.ncix.com/products/index.p...minorcatid=135

Product page of PC2-8500 with the Crucials a little down in the list. It nowhere shows the last parts of '.16fd3' or '.8fe5'. Even worse, if you really bought the parts you wrote down they're not even guaranteed to run in Dual Channel. And yes, the chance is very very small it wouldnt but well, guess you got unlucky but after all that's why the Dual Channel kits are invented.