Wierd Problem Need Help

HEy guys, still on this HP Pavilion 521c Desktop, I got a bunch of Ram Sticks and was trying to Run it off of 2 256mb sticks because i was running it off of 1 256mb before. so i pop in the new 256 stick i had. and then reboot and it kept beeping not booting up. i know this is a RAM problem. so i switch the 2 sticks and try, same thing. so i remove the one i put in and re seat the one i had it running off of in Bay 1 where it was running fine and i still get the same thing....i'm frustrated. why won't it read the Ram Stick? it was just working perfectly?! anyone able to help me trouble shoot this? thanks....I'm running Xubuntu 9.1 no Windows installed. all help is greatly appreciated. Thanks in Advanced.

P.S I have about 10 different Ram Sticks and NONE of them would work. some keep beeping and some don't beep at all but still wont boot.