diff --git a/lib/relation-definition.js b/lib/relation-definition.js
index 69dc2117..2167ecb5 100644
--- a/lib/relation-definition.js
+++ b/lib/relation-definition.js
@@ -128,6 +128,7 @@ RelationDefinition.prototype.toJSON = function () {
  * @param {Object} filter (where, order, limit, fields, ...)
  */
 RelationDefinition.prototype.applyScope = function(modelInstance, filter) {
+  filter = filter || {};
   filter.where = filter.where || {};
   if ((this.type !== 'belongsTo' || this.type === 'hasOne')
     && typeof this.discriminator === 'string') { // polymorphic
@@ -1537,19 +1538,19 @@ RelationDefinition.embedsMany = function embedsMany(modelFrom, modelTo, params)
   };
   
   var findByIdFunc = scopeMethods.findById;
-  modelFrom.prototype['__findById__' + relationName] = findByIdFunc;
+  modelFrom.prototype['__findById__' + accessorName] = findByIdFunc;
   
   var destroyByIdFunc = scopeMethods.destroy;
-  modelFrom.prototype['__destroyById__' + relationName] = destroyByIdFunc;
+  modelFrom.prototype['__destroyById__' + accessorName] = destroyByIdFunc;
   
   var updateByIdFunc = scopeMethods.updateById;
-  modelFrom.prototype['__updateById__' + relationName] = updateByIdFunc;
+  modelFrom.prototype['__updateById__' + accessorName] = updateByIdFunc;
   
   var addFunc = scopeMethods.add;
-  modelFrom.prototype['__link__' + relationName] = addFunc;
+  modelFrom.prototype['__link__' + accessorName] = addFunc;
 
   var removeFunc = scopeMethods.remove;
-  modelFrom.prototype['__unlink__' + relationName] = removeFunc;
+  modelFrom.prototype['__unlink__' + accessorName] = removeFunc;
 
   scopeMethods.create = scopeMethod(definition, 'create');
   scopeMethods.build = scopeMethod(definition, 'build');
@@ -1614,17 +1615,15 @@ EmbedsMany.prototype.findById = function (fkId, cb) {
   
   var embeddedList = modelInstance[relationName] || [];
   
-  fkId = fkId.toString(); // in case of explicit id
-  
   var find = function(id) {
     for (var i = 0; i < embeddedList.length; i++) {
       var item = embeddedList[i];
-      if (item[pk].toString() === fkId) return item;
+      if (item[pk].toString() === id) return item;
     }
     return null;
   };
   
-  var item = find(fkId);
+  var item = find(fkId.toString()); // in case of explicit id
   item = (item instanceof modelTo) ? item : null;
   
   if (typeof cb === 'function') {
@@ -1700,13 +1699,11 @@ EmbedsMany.prototype.destroyById = function (fkId, cb) {
     if (typeof cb === 'function') {
       modelInstance.updateAttribute(relationName, 
         embeddedList, function(err) {
-        cb(err, inst);
+        cb(err);
       });
     }
   } else if (typeof cb === 'function') {
-    process.nextTick(function() { 
-      cb(null, null); // not found
-    });
+    process.nextTick(cb); // not found
   }
   return inst; // sync
 };
@@ -1759,7 +1756,7 @@ EmbedsMany.prototype.create = function (targetModelData, cb) {
     return process.nextTick(function() { 
       cb(err, embeddedList); 
     });
-  } 
+  }
   
   modelInstance.updateAttribute(relationName, 
     embeddedList, function(err, modelInst) {
@@ -1782,7 +1779,11 @@ EmbedsMany.prototype.build = function(targetModelData) {
     var ids = embeddedList.map(function(m) { 
       return (typeof m[pk] === 'number' ? m[pk] : 0);
     });
-    targetModelData[pk] = (Math.max(ids) || 0) + 1;
+    if (ids.length > 0) {
+      targetModelData[pk] = Math.max.apply(null, ids) + 1;
+    } else {
+      targetModelData[pk] = 1;
+    }
   }
   
   this.definition.applyProperties(this.modelInstance, targetModelData);
@@ -1880,7 +1881,7 @@ EmbedsMany.prototype.remove = function (acInst, cb) {
     });
     
     modelInstance.save(function(err) {
-      cb(err, err ? [] : items);
+      cb(err);
     });
   });
 };