Well, you only showed me one side of the SIMM there. There could a voltage regulator on the other side, unless there is nothing on the other side except four more memory chips.

If there are just four more memory chips on the other side, then this is a 3.3V SIMM. Again, I don't know why you'd get 1/4 capacity out of it. I would expect it to not work at all. I'm also not so sure about there being 3.3V 72 pin SIMMs. But maybe there were.