[Plugin: wpsc Support Tickets] Undefined variable "output"

Hello,

I’m testing this plugin, but after configuring I don’t see nothing on the selected page. In the settings page I see the following error:

Notice: Undefined variable: output in wpsc-support-tickets.php on line 266

I’m using WP 3.4, the Responsive theme and the following plugins:

chatlive: http://ww.wp.xz.cn/extend/plugins/chatlive/
Cleverness To-Do List: http://ww.wp.xz.cn/extend/plugins/cleverness-to-do-list/
Configure SMTP

I’m looking at the code, but I don’t find the issue.

Thank you

http://ww.wp.xz.cn/extend/plugins/wpsc-support-tickets/