I'm seeing this in the simulator too, thank goodness (so much easier to debug!), and I noticed that if I change ENABLE_Z_BUFFER to 0 the problem goes away. I couldn't tell you why but if you're just doing wireframe drawing you won't need to worry about depth sorting so both ENABLE_Z_BUFFER and ENABLE_ORDERING_TABLE can be turned off.
But now there's a new problem:
Hm. I know I've fixed this problem before, but your render.c is up to date. Weird. Welp, here's a fix for that: render.c.zip (3.3 KB)
I'm surprised I never noticed that line overrun before. Thanks for pointing that out! (even if unintentionally 
)