Especially if you've not reset CMOS since changing CPU or updating BIOS definitely do it, then try enabling XMP for the memory. Also be sure to use the 2nd and 4th DIMM socket going away from the CPU if the mobo has 4 DIMM sockets.
Another trick is to manually set the DIMM voltage in BIOS; check memory labels or their package for the rated voltage. This is more frequently useful for getting 3600 memory to POST but can't hurt to try it with your 3200.