I'm surprised that these topics aren't covered by FatBurger's FAQ. Maybe we should PM him to update that...
Still, there are answers on the Crucial FAQ Search that he linked to in his FAQ.
Links to answers in Crucial's FAQ:
<A HREF="http://support.crucial.com/scripts/crucial.exe/solution?11=001018-0003&130=000971881378&14=&2715=&15=0&2716=0&57=search&58=&2900=U5jwDsMzRb&25=6&3=registered ecc" target="_new">Registered</A>
<A HREF="http://support.crucial.com/scripts/crucial.exe/solution?11=001115-0004&130=000974320480&14=&2715=&15=0&2716=0&57=search&58=&2900=U5jwDsMzRb&25=6&3=buffered" target="_new">Buffered</A>
<A HREF="http://support.crucial.com/scripts/crucial.exe/solution?11=010710-0007&130=000994780551&14=&2715=&15=0&2716=0&57=search&58=&2900=U5jwDsMzRb&25=6&3=registered ecc" target="_new">ECC</A>
<A HREF="http://support.crucial.com/scripts/crucial.exe/solution?11=000724-0009&130=000964475247&14=&2715=&15=0&2716=0&57=search&58=&2900=U5jwDsMzRb&25=6&3=cas" target="_new">CAS</A>
So hopefully these help you. If you still have questions, we'll try to answer them.
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