Associate
I'll try to get a pic of the power supply I've got and compare it to your PDF. However, didn't someone say they were shipped a replacement Power Supply that was one of the new ones? I assume if the pin-out is different, the whole monitor would need to be different, right? (or at least the port on the monitor itself)
Its unlikely that there will be any difference between the 24Wi and the 26Wi with the polarity, but its is worth checking before you plug it in.
On another note, can you not borrow a DVM from some body and compare the PSU`s themselves ?