Wrong variable name on line 317 in bpy_types.py
self.vertices.add(len(verts))
should be
self.vertices.add(len(vertices))

Also at some lines further down.

Traceback (most recent call last):
File "meshes.py", line 39, in <module>
File "meshes.py", line 27, in run
File "meshes.py", line 17, in createMesh
File "/home/thomas/apps/bf/2.56/scripts/modules/bpy_types.py", line 317, in from_pydata
self.vertices.add(len(verts))
NameError: global name 'verts' is not defined

Test file:

#----------------------------------------------------------
# File meshes.py
#----------------------------------------------------------
import bpy

def createMesh(name, origin, verts, edges, faces):
# Create mesh and object
me = bpy.data.meshes.new(name+'Mesh')
ob = bpy.data.objects.new(name, me)
ob.location = origin
ob.show_name = True
# Link object to scene
bpy.context.scene.objects.link(ob)

# Create mesh from given verts, edges, faces. Either edges or
# faces should be [], or you ask for problems
me.from_pydata(verts, edges, faces)

# Update mesh with new data
me.update(calc_edges=True)
return ob

def run(origin):
(x,y,z) = (0.707107, 0.258819, 0.965926)
verts1 = ((x,x,-1), (x,-x,-1), (-x,-x,-1), (-x,x,-1), (0,0,1))
faces1 = ((1,0,4), (4,2,1), (4,3,2), (4,0,3), (0,1,2,3))
ob1 = createMesh('Solid', origin, verts1, [], faces1)
verts2 = ((x,x,0), (y,-z,0), (-z,y,0))
edges2 = ((1,0), (1,2), (2,0))
ob2 = createMesh('Edgy', origin, verts2, edges2, [])

# Move second object out of the way
ob1.select = False
ob2.select = True
bpy.ops.transform.translate(value=(0,2,0))
return

if __name__ == "__main__":
run((0,0,0))