I bought this extension on August 26th for my Joomla 1.5.x site. When I tried to perform the OAUTH config, I got an http 500 INTERNAL SERVER ERROR. I have reproduced the same error on another fresh install of Joomla. I contacted the author and initially he asked me for logs and settings of my Joomla and php server. I send them to him; since August 30th I haven't received any news from the developper and he doesn't reply my e-mails just asking if he is still working on the problem.