cannot access task list and task related information from google account

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Generate oauth2 access token
2. make request to get task list, task from list etc..
3. get response 400 error, some time 401 error.

What is the expected output? What do you see instead?
will give me task list and task in json format.

What version of the product are you using? On what operating system?
 "Tasks API v1" I am using to integrate into mine web-application.

Please provide any additional information below.

I tried with given try_it link not getting task list. Tried with 
"https://developers.google.com/oauthplayground" also getting same error. Tried 
with rest client getting same error.

Error is blow: 

GET /tasks/v1/users/@me/lists/test HTTP/1.1
Host: www.googleapis.com
Content-length: 0
Authorization: OAuth 
ya29.ywDEvHTiQh0QTAM299SoIjL200aK0c-eGfKeaT7Ahta_PCHX5nLCAmqHKXCWUeyeKwstdXyOi7q
86A
HTTP/1.1 400 Bad Request
Content-length: 172
X-xss-protection: 1; mode=block
X-content-type-options: nosniff
Expires: Thu, 27 Nov 2014 14:59:53 GMT
Vary: Origin,X-Origin
Server: GSE
Cache-control: private, max-age=0
Date: Thu, 27 Nov 2014 14:59:53 GMT
X-frame-options: SAMEORIGIN
Content-type: application/json; charset=UTF-8
{
  "error": {
    "code": 400, 
    "message": "Invalid Value", 
    "errors": [
      {
        "domain": "global", 
        "message": "Invalid Value", 
        "reason": "invalid"
      }
    ]
  }
}

Original issue reported on code.google.com by sibanan...@gmail.com on 27 Nov 2014 at 3:05

[GoogleCodeExporter]

Response should be like : 

{
  "kind": "tasks#tasks",
  "etag": string,
  "nextPageToken": string,
  "items": [
    tasks Resource
  ]
}

Original comment by sibanan...@gmail.com on 27 Nov 2014 at 3:07