Rails routing acts weirdly - ruby-on-rails

Question

Suddenly my Rails application acts weirdly. If I attach an image on a edit page and submit the form, show action is called instead of update action. If I don't attach any image, it's ok.
Routes
namespace :admin do
resources :products do
collection do
get :download_images
get :all_styles
post :compress_images
end
end
end
View
%h1 Edit Product
= form_for [:admin, #product], :html => {:multipart => true} do |f|
- if f.object.accessory?
= render 'form_accessory', :f => f
- else
= render 'form', :f => f
[_form partial]
:javascript
function exclusiveCheck(check_box) {
if (check_box.checked) {
$('#pictures_fieldset .is_main').attr('checked', false);
check_box.checked = true;
}
}
- error_messages_for f.object
%fieldset.span-23
%legend
.row
= f.label :category_id, :class => "required"
%br
= f.select :category_id, array_of_categories('garment'), :include_blank => true
= f.check_box :new_in_category
= image_tag "new_icon.png"
.row
= f.label :style_no, :class => "required"
%br
= f.text_field :style_no, :style => "width: 5em;"
.row
= f.label :name, :class => "required"
%br
= f.text_field :name
.row
= f.label :fabric_info, :class => ""
%br
= f.text_field :fabric_info, :style => "width: 90%;"
.row
= f.label :lb_per_piece, "Weight", :class => "required"
%br
= f.text_field :lb_per_piece, :style => "width: 3em;"
.row
.span-3
= f.label :price, :class => "required"
%br
= f.text_field :price, :style => "width: 6em;"
.span-3
= f.label :original_price, :class => ""
%br
= f.text_field :original_price, :style => "width: 6em;"
.span-10
%label Discount Rate
%br
= text_field_tag :percent, nil, :style => "width: 3em;", :id => "percent"
= "%"
= link_to_function "Set", "setPrice();"
= f.check_box :new_in_sale
= image_tag "new_icon.png"
.row
= f.label :video, :class => ""
%br
= f.text_field :video, :style => "width: 15em;"
(Upload videos to data.ohyesfashion.com at ~/files/videos directory.)
.row
= f.label :available_on
%br
= f.text_field :available_on, :class => 'date'
.row
= f.check_box :active
= f.label :active, :class => ""
.row
= f.check_box :new_arrival
= f.label :new_arrival, :class => ""
= f.check_box :new_in_new_arrival?
= image_tag "new_icon.png"
.row
= f.check_box :best
= f.label :best, :class => ""
= f.check_box :new_in_best
= image_tag "new_icon.png"
.span-24.last
%button.button.positive(type="submit")
= icon_for(:accept, "Save")
%fieldset
%legend Sizes
- Product::SIZES.each do |size|
.span-2
= size.to_s.upcase
= f.select size, [*0..20].map { |i| i.to_s }
.span-24
.span-12
%fieldset
%legend Descriptions
- Description.order("code, name").each do |description|
.row
= check_box_tag "descriptions[]", description.id, f.object.descriptions.include?(description)
= "[#{description.code}]"
= description.name
.row
New Description
= text_field_tag :new_description_name
.span-12.last
%fieldset(style="float: right;")
%legend Colors
.span-11
- Color.order("name").each do |color|
.row
.span-1
= check_box_tag "colors[]", color.id, f.object.colors.include?(color)
.span-4
= color_box color
.span-3
= check_box_tag "sold_out_colors[]", color.id, (f.object.colors.include?(color) and Colorship.sold_out?(f.object, color))
Sold Out
.span-2
= check_box_tag "is_new_colors[]", color.id, (f.object.colors.include?(color) and Colorship.is_new?(f.object, color))
New
.span-24.last
%button.button.positive(type="submit")
= icon_for(:accept, "Save")
- (15 - f.object.pictures.size).times { f.object.pictures.build }
%fieldset#pictures_fieldset
%legend Images
.row
= f.label :model_id, "Model"
= f.select :model_id, PhotoModel.all.map { |i| [i.name, i.id] }, :include_blank => true
%br
= f.fields_for :pictures do |ff|
.span-7(style="height: 150px;")
- if ff.object.new_record?
= ff.file_field :image
- else
= image_tag ff.object.image.url(:w45)
%br
= ff.object.image_file_name
%br
= ff.check_box :is_main, :onclick => "exclusiveCheck(this)", :class => "is_main"
Title
%br
= ff.check_box "_destroy"
Delete
.span-24.last
= link_to icon_for(:back, "Back"), :back, :class => "button negative"
%button.button.positive(type="submit")
= icon_for(:accept, "Save")
:javascript
function setPrice() {
if ($('#product_original_price').val() != '' && $('#percent').val() != '') {
var originalPrice = parseFloat($('#product_original_price').val());
var percent = parseFloat($('#percent').val());
$('#product_price').val(originalPrice * (100 - percent) / 100.0);
}
}
Any idea what's going on? It used to work fine.