This might be related to bug 1067130, but I'm not sure, mark duplicate if needed.
In the attached script, the polygon is often miscoloured, or lacks vertexes. If I disable GL_COLOR_ARRAY, vertexes draw fine.
From what I get it seems that calling glColorPointer overwrites some data in vertex pointer and/or vice versa.
I get distorted views like http://img292.imageshack.us/img292/5295/bugwd1.jpg, while I should get the full polygon.
If I change the order of functions artifacts change too and sometimes disappear, but nothing predictable.
The similar program in C runs fine, so it is unlikely to be a driver issue.
System used: Ubuntu Linux, kernel 2.6.22