Dell R5400 Rack Workstation RAM upgrade - Help!!

Hi All,

I have just purchased some RAM for the above Dell and when upgrading I get the following message.

Alert! Invalid Memory. Dimms must have full heat spreaders. System halted.

RAM is DDR2 PC2-5300 • CL=5 • Fully Buffered • ECC • DDR2-667 • 1.8V • 512Meg x 72

Any help would be appreciated.

Thanks,

N