The problem is as follows:
1. I authorized my Dropbox Account
2. Once the auhtorizing process is finished, I can upload or browse the files of my Dropbox account.
3. But, if I click on anyother link of Service Builder that shows Dropbox files, the following error message is shown.
Warning: file_get_contents(https://api.dropbox.com/1/oauth/request_token) [function.file-get-contents]: failed to open stream: HTTP request failed! HTTP/1.1 401 Unauthorized in /home3/crookedb/public_html/servicebuilder/dropbox/DropboxClient.php on line 338 Fatal error: Uncaught exception 'DropboxException' with message 'Could not get request token!' in /home3/crookedb/public_html/servicebuilder/dropbox/DropboxClient.php:55 Stack trace: #0 /home3/crookedb/public_html/servicebuilder/dropbox/DropboxClient.php(88): DropboxClient->GetRequestToken() #1 /home3/crookedb/public_html/servicebuilder/application.php(2325): DropboxClient->BuildAuthorizeUrl('http://serviceb...') #2 /home3/crookedb/public_html/servicebuilder/application.php(2400): get_church_dropbox_secrets() #3 /home3/crookedb/public_html/servicebuilder/application.php(31): dropBox() #4 {main} thrown in /home3/crookedb/public_html/servicebuilder/dropbox/DropboxClient.php on line 55