It is possible that you got two bad boards in a row, but it is also possible the memory is slowly dying. I have seen inconsistent results like that before.
Since the board is two years out of support, you won't be able to swap it for another model. Sometimes you can do that in the first 30 days after purchase, but definitely not this long after.
If you have had the board less than three years, you can still apply for warranty replacement at Warranty Center . It shows:
Product:INTEL® WORKSTATION BOARD WX58BP, 10 PACK, OEM ONLY
Serial Number : BTBP1190009M
Stocking Id/Part Number : E64643-202
Estimated Warranty Expiration*: Feb 22,2015
so i think you might be okay.