UVs don't apply correctly on script-generated meshes

I'm having an issue with textures only applying to a small corner of some meshes I'm generating. The values I'm putting in scale from 0 to 1 as they should, and the meshes themselves are positioned correctly, but only one square segment is actually textured. I'm a bit lost as to what I'm doing wrong, and any help would be greatly appreciated. Full script is below (based on http://wiki.unity3d.com/index.php/CreatePlane), just attach to a GameObject. Most relevant bit starts at line 75.

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class ChunkManager : MonoBehaviour {
 
     public float chunkSize = 256;
     public int chunkSegs = 64;
     
     private GameObject map;
     private Dictionary<string, GameObject> chunks;
 
     private int vGridCount;
     private int vCount;
     private int tCount;
 
     private float scale;
     private float hSize;
     private float iSegs;
 
     // Use this for initialization
     void Start () {
         chunks = new Dictionary<string, GameObject> ();
         map = this.gameObject;
 
         vGridCount = chunkSegs + 1;
         vCount = vGridCount * vGridCount;
         tCount = chunkSegs * chunkSegs * 6;
 
         scale = chunkSize / (float)chunkSegs;
         hSize = chunkSize / 2.0f;
         iSegs = 1.0f / (float)chunkSegs;
 
         for (int x = -1; x < 2; x++) {
             for (int y = -1; y < 2; y++) {
                 CreateChunk (x, y);
             }
         }
     }
     
     // Update is called once per frame
     void Update () {
     
     }
 
     // Creates a new chunk
     void CreateChunk(float x, float z) {
         CreateChunk (Mathf.FloorToInt (x / chunkSize), Mathf.FloorToInt (z / chunkSize));
     }
 
     string GetChunkId(int cx, int cz) {
         return cx.ToString() + "-" + cz.ToString();
     }
     
     void CreateChunk(int cx, int cz) {
         string chunkid = GetChunkId (cx, cz);
 
         Debug.Log ("Creating chunk " + chunkid);
 
         // Create the chunk object
 
         GameObject chunk = new GameObject ();
         chunk.name = "Chunk " + chunkid;
         chunk.transform.parent = map.transform;
         chunk.transform.position = new Vector3((float)cx * chunkSize, 0.0f, (float)cz * chunkSize);
 
         // Build the mesh
 
         Mesh mesh = new Mesh();
 
         Vector3[] vertices = new Vector3[vCount];
         Vector2[] uvs = new Vector2[vCount];
         int[] triangles = new int[tCount];
 
         // Calculate uvs and vertices
 
         int offset = 0;
         float x, y;
         for (y = 0.0f; y < vGridCount; y++) {
             for (x = 0.0f; x < vGridCount; x++) {
                 vertices[offset] = new Vector3(x * scale - hSize, 0.0f, y * scale - hSize);
                 uvs[offset++] = new Vector2(x * iSegs, y * iSegs);
                 if (chunkid == "0-0" && y == 0.0f) {
                     Debug.Log (uvs[offset-1].x);
                 }
             }
         }
 
         // Calculate triangles
 
         offset = 0;
         int ix, iy, a, b, c, d;
         for (iy = 0; iy < chunkSegs; iy++) {
             for (ix = 0; ix < chunkSegs; ix++) {
                 a = ( iy      * vGridCount) + ix;
                 b = ((iy + 1) * vGridCount) + ix;
                 c = a + 1;
                 d = b + 1;
 
                 triangles[offset  ] = a;
                 triangles[offset+1] = b;
                 triangles[offset+2] = c;
 
                 triangles[offset+3] = b;
                 triangles[offset+4] = d;
                 triangles[offset+5] = c;
             }
         }
 
         // Update mesh
 
         mesh.vertices = vertices;
         mesh.uv = uvs;
         mesh.triangles = triangles;
         mesh.RecalculateNormals ();
         mesh.RecalculateBounds ();
 
         // Attach mesh filter and mesh renderer
         
         MeshFilter meshFilter = (MeshFilter)chunk.AddComponent (typeof(MeshFilter));
         MeshRenderer meshRenderer = (MeshRenderer)chunk.AddComponent (typeof(MeshRenderer));
         chunk.AddComponent (typeof(BoxCollider));
 
         meshFilter.sharedMesh = mesh;
         meshRenderer.sharedMaterial = new Material(Shader.Find("Diffuse"));
 
         chunks.Add (chunkid, chunk);
     }
 
 }