diff --git a/app/controllers/problems_controller.rb b/app/controllers/problems_controller.rb
--- a/app/controllers/problems_controller.rb
+++ b/app/controllers/problems_controller.rb
@@ -163,7 +163,7 @@
     @submissions.find_each do |sub|
       d = (DateTime.now.in_time_zone - sub.submitted_at) / 24 / 60 / 60
       @histogram[:data][d.to_i] += 1 if d < range
-      user[sub.user_id] = [user[sub.user_id], (sub.points >= @problem.full_score) ? 1 : 0].max
+      user[sub.user_id] = [user[sub.user_id], (sub.try(:points) >= @problem.full_score) ? 1 : 0].max
     end
     @histogram[:summary][:max] = [@histogram[:data].max,1].max
 
diff --git a/app/controllers/report_controller.rb b/app/controllers/report_controller.rb
--- a/app/controllers/report_controller.rb
+++ b/app/controllers/report_controller.rb
@@ -216,14 +216,37 @@
 
 
   def multiple_login
+    #user with multiple IP
     raw = Submission.joins(:user).joins(:problem).where("problems.available != 0").group("login,ip_address").order(:login)
     last,count = 0,0
-    @multiple = []
+    first = 0
+    @users = []
     raw.each do |r|
       if last != r.user.login
         count = 1
+        last = r.user.login
+        first = r
       else
-        @multiple << r
+        @users << first if count == 1
+        @users << r
+        count += 1
+      end
+    end
+
+    #IP with multiple user
+    raw = Submission.joins(:user).joins(:problem).where("problems.available != 0").group("login,ip_address").order(:ip_address)
+    last,count = 0,0
+    first = 0
+    @ip = []
+    raw.each do |r|
+      if last != r.ip_address
+        count = 1
+        last = r.ip_address
+        first = r
+      else
+        @ip << first if count == 1
+        @ip << r
+        count += 1
       end
     end
   end
diff --git a/app/controllers/user_admin_controller.rb b/app/controllers/user_admin_controller.rb
--- a/app/controllers/user_admin_controller.rb
+++ b/app/controllers/user_admin_controller.rb
@@ -84,11 +84,16 @@
           added_random_password = true
         end
 
-        user = User.new({:login => login,
-                          :full_name => full_name,
-                          :password => password,
-                          :password_confirmation => password,
-                          :alias => user_alias})
+        user = User.find_by_login(login)
+        if user
+          user.password = password
+        else
+          user = User.new({:login => login,
+                            :full_name => full_name,
+                            :password => password,
+                            :password_confirmation => password,
+                            :alias => user_alias})
+        end
         user.activated = true
         user.save
 
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -13,7 +13,7 @@
       append_to menu_items, '[Problems]', 'problems', 'index'
       append_to menu_items, '[Users]', 'user_admin', 'index'
       append_to menu_items, '[Results]', 'user_admin', 'user_stat'
-      append_to menu_items, '[Report]', 'report', 'login_stat'
+      append_to menu_items, '[Report]', 'report', 'multiple_login'
       append_to menu_items, '[Graders]', 'graders', 'list'
       append_to menu_items, '[Contests]', 'contest_management', 'index'
       append_to menu_items, '[Sites]', 'sites', 'index'
diff --git a/app/models/user.rb b/app/models/user.rb
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -67,11 +67,11 @@
     user = find_by_login(login)
     if user
       return user if user.authenticated?(password)
-      if user.authenticated_by_cucas?(password) or user.authenticated_by_pop3?(password)
-        user.password = password
-        user.save
-        return user
-      end
+#      if user.authenticated_by_cucas?(password) or user.authenticated_by_pop3?(password)
+#        user.password = password
+#        user.save
+#        return user
+#      end
     end
   end
 
diff --git a/app/views/problems/stat.html.haml b/app/views/problems/stat.html.haml
--- a/app/views/problems/stat.html.haml
+++ b/app/views/problems/stat.html.haml
@@ -34,6 +34,7 @@
         %th Submitted_at
         %th Points
         %th comment
+        %th IP
     %tbody
       - row_odd,curr = true,''
       - @submissions.each do |sub|
@@ -46,6 +47,7 @@
           %td= time_ago_in_words(sub.submitted_at) + " ago"
           %td= sub.points
           %td.fix-width= sub.grader_comment
+          %td= sub.ip_address
 - else
   No submission
 
diff --git a/app/views/report/multiple_login.html.haml b/app/views/report/multiple_login.html.haml
--- a/app/views/report/multiple_login.html.haml
+++ b/app/views/report/multiple_login.html.haml
@@ -6,6 +6,9 @@
 
 =render partial: 'report_menu'
 
+Checking for all submissions with the currently available problem
+
+%h2 Users with Multiple IP
 %table.tablesorter-cafe#my_table
   %thead
     %tr
@@ -13,8 +16,22 @@
       %th full name
       %th IP
   %tbody
-    - @multiple.each do |l|
+    - @users.each do |l|
       %tr{class: cycle('info-even','info-odd')}
-        %td= link_to l[:login], controller: 'users', action: 'profile', id: l[:id]
-        %td= l[:full_name]
+        %td= link_to l.user.login, controller: 'users', action: 'profile', id: l[:id]
+        %td= l.user.full_name
         %td= l[:ip_address]
+
+%h2 IP with multiple users
+%table.tablesorter-cafe#my_table
+  %thead
+    %tr
+      %th IP
+      %th login
+      %th full name
+  %tbody
+    - @ip.each do |l|
+      %tr{class: cycle('info-even','info-odd')}
+        %td= l[:ip_address]
+        %td= link_to l.user.login, controller: 'users', action: 'profile', id: l[:id]
+        %td= l.user.full_name