Replying to Broken RAM?

So i jsut bought some new ram today, it works fine, but my computer now randomly crashes about ever 5-10 mins.....i take the new stick of ram out and it works fine again.... is this a coomon thing to happen to ram or whats up? and the stick at leats partcially wokrs ebacsue i loke dta some stuff and it sai dmy computer was using some of it.... but then once inahiwle thigns go bam!!

its a 512mb pc2700 333ddr stick....and i had 2 of them in, whihc is supported by my comp. but the new one is fucked.