For the MS4348PE inverters, did the UPS mode fix the problem? I believe the 110vac readings are a result of some of the meters not being updated by Magnum – they are still displaying the US voltage numbers instead of the European or 230vac numbers.
If the servers are still shutting off on UPS mode, then you might have some of those new servers with the cheap power supplies that have hardly any capacitors in them. They cannot tolerate much of a break in power. You might try either putting a UPS in between the inverter and server or possibly changing inverters – the Xantrex XW claims a shorter transfer time, but not sure it is true. Very hard to measure.