[YouTube-API] Suddenly started getting error

We started getting this error some time ago, when uploading a video to
YouTube via the API.

problem uploading: HTTP/1.1 401 Unauthorized
Server: HTTP Upload Server Built on Mar 21 2012 14:55:22 (1332366922)
X-GData-User-Country: US
WWW-Authenticate: GoogleLogin realm="https://accounts.google.com/
ClientLogin",service="youtube"
Content-Type: text/html; charset=UTF-8
Content-Length: 13
X-GUploader-UploadID:
AEnB2UpOzVHcpI3jvJJMjYJiITLqEtXSx3kNhylKXjOIHZd4AaaliFBrwsGcgUSTFE3Sz2f16Hgg7VVZJeN6l_A4yT66qfVlHQ
Date: Thu, 22 Mar 2012 12:52:24 GMT
Pragma: no-cache
Expires: Fri, 01 Jan 1990 00:00:00 GMT
Cache-Control: no-cache, no-store, must-revalidate
Connection: close

Token expired

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