What causes this graphical bug on walls?

[sameson11]

Chief X4

What causes this weird graphical anomaly?
This is a two story wall. I made sure they were aligned. There are stairs running underneath if that makes any difference. But it does seem to when I removed the stairs.

It's more of annoyance than anything. I've seen it crop up in other random areas.

[sutcac]

See if this thread helps-


http://www.chieftalk.com/showthread.php?t=56731