Just installed Tracks 2.1 in my local box, but I got very strange behavior from Tracks.

Steps to reproduce
1. Fill in description, project (existed), context (existed) and due date on the new Action form.
2. Click "Add action" button

Expected result:
The action will be created with no any mistake.

Actual result:
1. System shows message "There was an error retrieving from server: error".
2. There is a dialog popup saying "New context 'XXXXX" will be also created. Are you sure?", "XXXXX" is actually an existed context.
3. After clicking "Yes", the action could be created.

I attached the screenshot.

There is no error message stored in log file.
And in my another environment, same code, same database but has no this issue.

Environment information:
OS: Ubuntu Server 3.2.0-24-virtual
Database: sqlite3
Ruby: 1.8.7
Using rake (0.8.7)
Using RedCloth (4.2.8)
Using ZenTest (4.6.2)
Using aasm (2.2.1)
Using activesupport (2.3.14)
Using rack (1.1.0)
Using actionpack (2.3.14)
Using actionmailer (2.3.14)
Using activerecord (2.3.14)
Using activeresource (2.3.14)
Using acts_as_list (0.1.4)
Using aruba (0.2.2) from source at vendor/gems/aruba-0.2.2
Using bcrypt-ruby (2.1.4)
Using builder (3.0.0)
Using mime-types (1.17.2)
Using nokogiri (1.4.7)
Using rack-test (0.6.1)
Using ffi (1.0.11)
Using childprocess (0.3.1)
Using multi_json (1.1.0)
Using rubyzip (0.9.6.1)
Using selenium-webdriver (2.20.0)
Using xpath (0.1.4)
Using capybara (1.1.2)
Using cgi_multipart_eof_fix (2.5.0)
Using columnize (0.3.6)
Using diff-lcs (1.1.3)
Using json (1.6.5)
Using gherkin (2.7.7)
Using term-ansicolor (1.0.7)
Using cucumber (1.1.4)
Using cucumber-rails (0.3.2)
Using daemons (1.1.8)
Using database_cleaner (0.7.1)
Using fastthread (1.0.7)
Using flexmock (0.9.0)
Using gem_plugin (0.2.3)
Using has_many_polymorphs (2.13) from source at vendor/gems/has_many_polymorphs-2.13
Using highline (1.5.2)
Using hoe (2.13.1)
Using hpricot (0.8.6)
Using htmlentities (4.3.1)
Using httpclient (2.2.4)
Using i18n (0.6.0)
Using rbx-require-relative (0.0.5)
Using linecache (0.46)
Using polyglot (0.3.3)
Using treetop (1.4.10)
Using mail (2.4.1)
Using memory_test_fix (0.1.3)
Using mongrel (1.1.5)
Using mysql (2.8.1)
Using rails (2.3.14)
Using rspec (1.3.2)
Using rspec-rails (1.3.4)
Using ruby-debug-base (0.10.4)
Using ruby-debug (0.10.4)
Using ruby-openid (2.1.8)
Using rubycas-client (2.2.1)
Using rubyjedi-actionwebservice (2.3.5.20100714122544)
Using sanitize (1.2.1)
Using soap4r (1.5.8)
Using sqlite3 (1.3.5)
Using test-unit (1.2.3)
Using thoughtbot-factory_girl (1.2.2)
Using will_paginate (2.3.16)
Using yard (0.7.5)
Using bundler (1.2.1)