ZDoom Conveyor Dummy Desync

I was making a map earlier, but came acrosss an issue and could not solve it or find anybody who had previously had such an issue, so I was wondering if somebody here may be able to assist. In said map is a section with four pillars, raising and falling in sync. One pillars starting to go up coincided with the pillar one stage anti-clockwise going down - same for stopping. This works perfectly fine in both PRBoom+ and Eternity, but ZDoom (and Zandronum act strangely). Zandronum desyncs for the initial lowering of all four pillars, but is syncronised after, whereas ZDoom is 100% desynced 100% of the time. This is an issue even after tweaking about various compatibility flags. Below is a link to an ugly as sin demonstration wad to show what exactly happens (and also aid those who may not understand my explanation).
https://dl.dropboxusercontent.com/u/36523265/ZDoomisms.wad

I let it progress through the sequence about 15 times in zdoom-x64-2.8pre-1615-gf10416a, no desync occurred.

This lacks one important piece of info:

Which version of ZDoom did you use?

I can't recall what version I was using before (it had the exact same issue so I tried updating), but am using the latest official Zandronum release, gzdoom-g2.1.pre-1159-gfbefe13, and zdoom-2.8pre-1658-g3adda34 (DRD Team Development Builds). Sorry for leaving that out.

Edit: I've made a video of what happens in ZDoom, for some reason Fraps is stupid and won't let me capture PRBoom+/Eternity. What should happen is that the pillars start and stop moving at the same time.

Edit 2: Thanks to Edward850 I was able to correct a couple things that may have been causing the issue, sadly it is still present. Here is the updated map: https://dl.dropboxusercontent.com/u/36523265/ZDoomisms_REDUX.wad