I suggest that you first check the RAM module in some other PC that supports DDR2. That way you can isolate a defective RAM. What happens with the first slot? Does it boot properly?
Have you checked the memory configuration in the BIOS setup. The updation might have reset the RAM frequency to something not supported. If the Kingston memory is built for 800 MHz then the BIOS update might have reset it to some other frequency. Check that also.
Get a RAM from another computer to fix in this computer. Try it to confirm. Otherwise check the Intel website to see what all are being upgraded with the upgrade package.
Keep me posted.