Unable to complete the operation

[demdeberanz]

Hi guys,
   I'm using QueryTask to perform a lot of query on the same layer in sequence. I've managed this task in other JS script with success.
Now It getting me the following error: "Error: Unable to complete operation." for every query I perform. Other times it gives me this error just for some queries.

Can anyone help me?

Thank you everybody.

[nicogis]

if you do the request direct to rest have you same problem (see in firebug net or fiddler the request)?