Website's Modify Inline button broken?

[Bogus Noise]

Just thought I'd give you a heads up - saw in a thread the missing image icon in place of the image that's meant to be located here:

http://www.circuitbenders.co.uk/forum/Themes/matrix/images/icons/modify_inline.gif

[Circuitbenders]

That one on the bottom right of the post there?

Has it ever been there? I have no idea what 'modify inline' actually does.

[Bogus Noise]

Well, I'd never noticed anything there until today 

It seems it's for editting your posts within the topic page rather than having to go to a separate page to edit.

Wasn't sure if it was something I'd never seen or if you'd been adding new things to the forum.