Dell Precision M90 Laptop Workstation Memory Upgrade Issues

Hello,

I recently purchased a Dell Precision M90 in supper condition.  These machines are built like tanks. I always wanted one, but they were very expensive.  It came with 2 modules of 1gb memory modules PC2-5300 667MHZ, for a total of 2gb.  I want to increase the Ram to 4gb total.  I bought what I thought was the right Ram.  I bought 2 modules of 2gb PC2-5300 DDR2 667MHZ.  I placed the Ram into the machine, but when I turned on the machine, the three scroll indicators lights next to the bluetooth indicator light kept flashing.  As soon as I placed the original Ram in, it turned on.  So, I decided to purchase the same brand of memory that came with it.  It came with samsung, so I did some research and found the 2gb equivalent to the 1gb Samsung memory modules.  I bought 2 modules of 2gb Samsung  M470T5663QZ3-CE6 PC2-5300S 667MHZ  memory modules today on EBAY.  My question is, are those the correct RAM for the Dell Precision M90 Laptop.  If not, can you please tell me which are.  Thank you.