undefined method `upload_column'

Hi list,

Saya lagi mo coba uploadcolumn plugin untuk menangani upload file. Saya
sudah menambahkan "upload_column :src_file" di model saya (seperti yang
diinstruksikan dalam README). Pas jalankan form upload-nya, saya dapat
NoMethodError. Ini full trace-nya:

/usr/lib/ruby/gems/1.8/gems/activerecord-2.1.0/lib/active_record/base.rb:1667:in
`method_missing'
app/models/speech.rb:2
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:215:in
`load_without_new_constant_marking'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:215:in
`load_file'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:354:in
`new_constants_in'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:214:in
`load_file'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:95:in
`require_or_load'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:260:in
`load_missing_constant'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:467:in
`const_missing'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:479:in
`const_missing'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:485:in
`send'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:485:in
`const_missing'