to your system ?
I currently have a "LanParty UT nF4 Ultra-D" mb with 2 x 512mb ddr400 ram, which are different brands. everything works perfectly, until i add my third piece of ram which is also 512mb ddr400 and also another brand.
when the computer is turned on, i get long repetitive beeps from the bios code which i found means that the RAM is either faulty or not seated properly. i have checked that the RAM works by placing it in the second slot, and checked numerous times that it is seated properly.
i have tried multiple combinations (1-2-3, 1-3-4, 1-2-4, 2-3-4) and nothing seems to work.
i know its not something to do with the double and single sided RAM because i already have one of each installed.
Windows XP Home
Processor - AMD 3700+
MOBO - LanParty UT nF4 Ultra-D
RAM - 2 x 512mb ddr 400
Video - Nvidia 7900GT
PSU - 430W