I have designed a simple CPCI board (no PCI signals) using the LTC1643 hotswap controller. It works fine when I hotswap this board in a CPCI chassis. But if I hotswap the redudant PSU sometimes the board gets shutdown power completely. Could this be the problem with my board or the PSUs ? I measure the power rail transient while hotswapping PUS and they all look good enough --all are within the LTC1643's shutdown limit. Anyone has similar experience could be shared?