Wood is not planks.

src/main/java/com/gmail/nossr50/datatypes/skills/MaterialType.java

@@ -21,7 +21,7 @@ public enum MaterialType {
                 return Material.LEATHER;
 
             case WOOD:
-                return Material.OAK_WOOD;
+                return Material.OAK_PLANKS;
 
             case STONE:
                 return Material.COBBLESTONE;

src/main/java/com/gmail/nossr50/util/ItemUtils.java

@@ -681,6 +681,18 @@ public final class ItemUtils {
             case JUNGLE_LOG:
             case OAK_LOG:
             case SPRUCE_LOG:
+            case OAK_WOOD:
+            case ACACIA_WOOD:
+            case BIRCH_WOOD:
+            case DARK_OAK_WOOD:
+            case STRIPPED_ACACIA_WOOD:
+            case JUNGLE_WOOD:
+            case SPRUCE_WOOD:
+            case STRIPPED_BIRCH_WOOD:
+            case STRIPPED_DARK_OAK_WOOD:
+            case STRIPPED_JUNGLE_WOOD:
+            case STRIPPED_OAK_WOOD:
+            case STRIPPED_SPRUCE_WOOD:
             case STRIPPED_ACACIA_LOG:
             case STRIPPED_BIRCH_LOG:
             case STRIPPED_DARK_OAK_LOG:

src/main/java/com/gmail/nossr50/util/skills/SkillUtils.java

@@ -255,7 +255,7 @@ public class SkillUtils {
             return Material.COBBLESTONE;
         }
         else if (ItemUtils.isWoodTool(inHand)) {
-            return Material.OAK_WOOD;
+            return Material.OAK_PLANKS;
         }
         else if (ItemUtils.isLeatherArmor(inHand)) {
             return Material.LEATHER;