It COULD, as cMP 4.1 and 5.1 are not that picky. However, if it works, it will only work at 1066MHz or 1333MHz depending on firmware and CPU.
It could be that the cMP is a bit more picky about ECC memory outside of the officialy supported range (PC8500/PC10600). This is not really the case with non-ECC memory, anything seems to go. The only real way to find out is to test it yourself