I think the MSI am1i mobo has an AMI BIOS.
3 beeps - Base 64K memory failure - bad memory
Reduce it to one stick and install it in the second slot.
Most mobos require you to stagger ram, with slots 2 and 4 being the first used. You can confirm all of this info by referencing your motherboard manual.
1 2 3 4
B A B A