Before finalizing my order on Amazon.com, I did research on the Internet to check whether these Komputerbay memory modules (2 x 1GB DDR DIMM (184 PIN) 400Mhz PC3200 CL 3.0 High-Density Memory) would be (or not) compatible with my motherboard.
The website of French Komputerbay is indigent and nothing appears on the compatibility of their memory modules (in my case, an ASUS P4P800 DeLuxe motherboard with an Intel Pentium 4 HT 2.8 HHz).
Decision: Products returned to Amazon.com and Komputerbay.