ECS D6VAA memory question...

Just finished a new dual PIII/1ghz system. All my 256mb/128mb SDRAM I have works fine in it. My problem is I have [3] 512mb sticks of Crucial SDRAM, PC133 • CL=3 • Unbuffered • Non-parity • 7.5ns • 3.3V • 64Meg x 64 that do not work right... failure to post, hangs etc.

Do I need:
unbuffered/ecc [64Meg x 72]?
registered/ecc [64Meg x 72]?

To make the board work with 512s? It is supposed to handle 1.5gb of memory in it's 3 DIMM slots. Board is a revision 1.0/non raid.

Thanks for the help

try taking 1 stick of the 512 crucial ram out ans see if it will post.
maybe the chipset can't handle more than 1gb.