Roundcube Joomla setup

[mortveiare]

I'm setting up roundcube on a joomla 1.5 site. However, I'm not seeing any information on the processes, and I keep getting an error whenever I try to use an applet. I'm not seeing a section on the wiki page for setting it up on a Joomla site. Please help.

The error I am getting is
Fatal error: Call to a member function is_error() on a non-object in /home5/heartofc/public_html/tbah/components/com_roundcube/index.php on line 138