Docm's advice is about the distance between two villages.
Your target is to build one village and another one far enough from the first to be counted as another and not the same village.
As the distance of your villages is 75 and the minimal distance between villages needs to be at least radius+32 Blocks, while radius describes the distance between the first village's center and the furthest door of it, your villages shoul be far enough from another.
There are now two error sources:
Either you have got any door between these two "villages" which connects them to one large, or you are too standing too far away from the not-working platform.
In the first case, destroy the doors in the middle.
If you haven't got any doors in between these villages, just try to play/stand/run whatever between them.
Depending on the servers configuration there is a limit of blocks that may be between you and the mobs (usually about 60-80 blocks). If you are too far away the mobs chunk stops working. This means, the mobs are not running around, not spawning anything and for sure not breeding anymore.
So, to get your farm working properly, make sure that all chunks of the farm are loaded.
Which you may either achieve by being between them or putting one of your friends at he bottom spawn layer and yourself at the upper.
Depending on which plugins are installed on the Server there may be even a block or something called "chunk loader" but one of them at the bottom-spawn-area and your problem is solved.
Ok, I figured it out... I guess I didn't provide enough detail to answer the question.
I had lowered the ceiling of the farm to 3 blocks, because Iron Golems are 2.9 blocks high. However, I found a detailed post about villages and iron golems on the forums and the guy said they require 4 blocks to spawn. They also only spawn in 6 blocks of vertical space, as well, so the placement of my doors and villagers meant that the top spawning pad was out of range (too high).
So to fix it, I had to raise the ceiling of the farm, as well as the doors and villagers, one block up, so that there is 4 vertical blocks of space on the first pad, and the second pad is within the right range of the "village" center.
Best Answer
Some servers restrict iron drops from iron golems to prevent the building of giant automated farms, or restrict any drops from environmentally-killed monsters, again, to prevent the creation of giant automated farms.
This might be done for gameplay reasons (no supplies of infinite free stuff) or for server lag reasons (no concentrations of hundreds or thousands of monsters collected in a tiny spot).