ERROR: Could not retrieve base url correctly

Hi,

I use RestAPI in a nuxeo client for sending files and for searching documents.
I've in serveur log file the error :  [BaseURL] Could not retrieve base url correctly

Somebody has an idea about it ?

The configuration is : 
  Nuxeo      : 5.1.5GA
  Database : mysql5.0.27
  System    : Linux redhat 5.2.1
  Jboss       : 4.0.4GA

Thx
Pascal