Remove Artifacts button does not work

Problem
In Bamboo version 4.4.0 and 4.4.4, the Remove Artifacts button does not work.

Steps to reproduce

1. Create a simple Script Task in the job, like this:

   echo "Hello" > artifact.txt
   

2. Create an artifact definition, like this:

   Name: test
   Location: <empty>
   Copy Pattern: artifact.txt
   

3. Run the plan
4. The file will be created at BAMBOO_HOME\xml-data\build-dir\PROJ-PLAN-JOB1\artifact.txt
5. Go to the build results page, Artifacts tab, and click "Remove Artifacts".
6. The requests to delete the artifacts can be seen in the logs:

   2013-03-20 11:00:20,589 INFO [qtp2026789660-134] [AccessLogFilter] admin POST http://localhost:8085/chain/result/removeChainArtifacts.action 63752kb
   2013-03-20 11:00:20,615 DEBUG [qtp2026789660-134] [AccessLogFilter] END: admin POST http://localhost:8085/chain/result/removeChainArtifacts.action 63752kb-880kb 26ms
   2013-03-20 11:00:20,624 INFO [qtp2026789660-132] [AccessLogFilter] admin POST http://localhost:8085/chain/result/removeChainArtifacts.action 62870kb
   2013-03-20 11:00:20,732 DEBUG [qtp2026789660-132] [AccessLogFilter] END: admin POST http://localhost:8085/chain/result/removeChainArtifacts.action 62870kb-2956kb 108ms
   

7. But the artifact can still be found at BAMBOO_HOME\xml-data\build-dir\PROJ-PLAN-JOB1\artifact.txt.