[Plugin: Redirection] Trailing Slash

I’ve seen a few topics on this subject but they’ve been closed.

https://img.skitch.com/20110725-e9s7j6m9u317yhjr1tu4frhhnw.jpg This redirect works when you go to;

http://www.flat-e.com/ionisation (no trailing slash)

but 404s if you go to;

http://www.flat-e.com/ionisation/ (trailing slash)

WordPress correctly canonicalises other urls on my site. Any advice appreciated. Thanks.

http://wordpress.org/extend/plugins/redirection/