Any query leads to "error code 4422: There is no data to show" answer...

Any query leads to "error code 4422: There is no data to show" answer...

Hello,

I have been writing some PHP code to get access to some data stored in our Zoho CRM following the Developer API Help pages but I keep getting the error code 4422: There is no data to show, no matter which query I send. Even a really simple one given in the examples fails:
https://crm.zoho.com/crm/private/xml/Leads/getMyRecords?newFormat=1&authtoken=MyAuthTokenGeneratedFollowingInstructions&scope=crmapi

No doubt I must be doing something wrong, but what???

To be sure the problem does not come from my code, I used the URL above in a browser (firefox and chrome) and still get the same message. Should this way work or this is to be expected?

Any help would be greatly appreciated.