Call to undefined function: fscache_is_file_stored()

I have installed Drupal 4.6.0, and filestore2 cvs module.

When I want to upload a new file (using ?q=node/add/filestore2), I got the following error message:

Fatal error: Call to undefined function: fscache_is_file_stored() in /home/iesdonan/public_html/modules/filestore2.module on line 427