Rails - Aug 2009 - get this error: "A copy of * has been removed from the module tree but is still active!"

Hi,

In one of my javascript functions I do two consecutive GET (ajax)
requests in quick succession. I get the following error in Rails
version 2.3.3 but not in 2.3.2. If I give a time lag (even 500ms)
between to two requests the problem vanishes!!:

----
 ArgumentError

    in StudentsController#index

<pre>A copy of StudentsController has been removed from the module
tree but is still active!</pre>

Sometimes I also get ''A copy of AuthenticatedSystem has been removed
from the module tree but is still active!'' error.

Someone else has also been having a similar problem (http://
railsforum.com/viewtopic.php?id=33976)

The application trace is:

    <div id="Application-Trace" style="display:
block;">
     
<pre><code>/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.3/lib/
active_support/dependencies.rb:414:in `load_missing_constant''
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.3/lib/active_support/
dependencies.rb:96:in `const_missing''
/home/~/app/controllers/students_controller.rb:4:in
`index''</code></
pre>
    </div>

    <div id="Framework-Trace" style="display: none;">
     
<pre><code>/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.3/lib/
active_support/dependencies.rb:414:in `load_missing_constant''
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.3/lib/active_support/
dependencies.rb:96:in `const_missing''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
base.rb:1327:in `send''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
base.rb:1327:in `perform_action_without_filters''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
filters.rb:617:in `call_filters''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
filters.rb:610:in `perform_action_without_benchmark''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
benchmarking.rb:68:in `perform_action_without_rescue''
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.3/lib/active_support/
core_ext/benchmark.rb:17:in `ms''
/usr/lib/ruby/1.8/benchmark.rb:308:in `realtime''
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.3/lib/active_support/
core_ext/benchmark.rb:17:in `ms''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
benchmarking.rb:68:in `perform_action_without_rescue''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
rescue.rb:160:in `perform_action_without_flash''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
flash.rb:146:in `perform_action''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
base.rb:527:in `send''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
base.rb:527:in `process_without_filters''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
filters.rb:606:in `process''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
base.rb:391:in `process''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
base.rb:386:in `call''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
routing/route_set.rb:434:in `call''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
dispatcher.rb:88:in `dispatch''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
dispatcher.rb:111:in `_call''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
dispatcher.rb:82:in `initialize''
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.3/lib/active_record/
query_cache.rb:29:in `call''
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.3/lib/active_record/
query_cache.rb:29:in `call''
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.3/lib/active_record/
connection_adapters/abstract/query_cache.rb:34:in `cache''
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.3/lib/active_record/
query_cache.rb:9:in `cache''
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.3/lib/active_record/
query_cache.rb:28:in `call''
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.3/lib/active_record/
connection_adapters/abstract/connection_pool.rb:361:in `call''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/head.rb:9:in `call''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/methodoverride.rb:
24:in `call''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
params_parser.rb:15:in `call''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
session/cookie_store.rb:93:in `call''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
reloader.rb:29:in `call''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
failsafe.rb:26:in `call''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/lock.rb:11:in `call''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/lock.rb:11:in
`synchronize''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/lock.rb:11:in `call''
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/action_controller/
dispatcher.rb:106:in `call''
/usr/lib/ruby/gems/1.8/gems/rails-2.3.3/lib/rails/rack/static.rb:31:in
`call''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/urlmap.rb:46:in `call''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/urlmap.rb:40:in `each''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/urlmap.rb:40:in `call''
/usr/lib/ruby/gems/1.8/gems/rails-2.3.3/lib/rails/rack/log_tailer.rb:
17:in `call''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/content_length.rb:
13:in `call''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/chunked.rb:15:in
`call''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/handler/mongrel.rb:
61:in `process''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:159:in
`process_client''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in `each''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in
`process_client''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `run''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in
`initialize''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `new''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `run''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in
`initialize''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `new''
/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `run''
/usr/lib/ruby/gems/1.8/gems/rack-1.0.0/lib/rack/handler/mongrel.rb:
34:in `run''
/usr/lib/ruby/gems/1.8/gems/rails-2.3.3/lib/commands/server.rb:111
/usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in
`gem_original_require''
/usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in
`require''
script/server:3</code></pre>