upload issue

[shoaibhussan]

hellow every body
i m facing the following issue
.
.
[WARNING] DropboxSDK: error making request to /1/files_put/dropbox/view.pdf - Authentication failed
2012-10-11 15:37:55.640 FastCase[638:207] File upload failed with error - Error Domain=dropbox.com Code=401 "The operation couldn’t be completed. (dropbox.com error 401.)" UserInfo=0xd42c040 {error=Authentication failed, destinationPath=/view.pdf, sourcePath=/Users/svp/Library/Application Support/iPhone Simulator/4.2/Applications/5DD0B9F3-B873-4844-9FDF-69AEAB5DF3F7/Documents/view.pdf}

any body help plzzzz
thx in advance