Wow that is odd. I'm guessing your RAM is either bad (not always the case) or the RAM isn't compatible with your system (most likely).
Here is what Lenovo lists for RAM types (of coarse their branded RAM, but good for reference):
Choice of available Lenovo 1GB, 2GB and 4GB DDR3 1333 SODIMM memories:
Lenovo 1GB DDR3 1333 SODIMM memory (78Y7383)
Lenovo 1GB DDR3 1333 SODIMM memory - Japan (78Y7384)
Lenovo 2GB DDR3 1333 SODIMM memory (78Y7392)
Lenovo 4GB DDR3 1333 SODIMM memory (78Y7385)
Lenovo 4GB DDR3 1333 SODIMM memory - Japan (78Y7386)
Lower 1.5V power consumption, compared to older 1.8V DDR2 memory, extends battery life
Improved system-level thermal management that further reduces power drain
Test-proven 100% compatibility listed for supported systems
CAS Latency: 9
Capacity: 1 GB / 2 GB / 4GB
Form Factor: SODIMM
Memory speed: 1333Mbps (667MHz)
Number of Pins: 204
Parity: Non-Parity
Pin Alloy: Cu/Ni/Au
RAM type: DDR3 SDRAM
So if it is 1.5v and up to 1333 Mhz (your 1600 Mhz should just go down to 1333 Mhz without issues) you should be fine. If you can give me the Model of RAM that you have, maybe we can see more details on the RAM that you bought.