Data API via curl

Data API via curl

Dears,
I have a very strange problem with Zoho data API via curl.

I have a database called Monitoring which contains a Table called Test with two columns (ID, Value).

If I try to add an element via curl with the command 
  1. curl -d "ZOHO_ACTION=ADDROW&ZOHO_OUTPUT_FORMAT=JSON&ZOHO_ERROR_FORMAT=JSON&ZOHO_API_VERSION=1.0&authtoken=<my token>&ID=2&Value=3" https://reportsapi.zoho.eu/api/<my e-mail>/Monitoring/Test   
I always obtain the answer 
  1. {
  2.  "response":{
  3.    "action":"ADDROW",
  4.    "error":{
  5.      "code":8518,
  6.      "message":"You need to (re)login to perform this operation"
  7.    }
  8.  }
  9. }
The strange thing is that if I try to use the same authtoken with ZohoUploadTool it works.
I've tryed to generate a new authtoken calling via browser the URL 
but nothing change.

I'm going to be crazy with this behaviour.
Can someone help me please? 

Michele