1.7.1 So there has been a bug with DeluxeMenus for quite some time now that I could never replicate so I kind of left it alone.....
In some weird cases, or with certain hack clients, players can open a menu, then obtain all of the items from the menu :/
Over the past few days myself and @Disorbs have been testing many different things to try and pinpoint the source of the problem and I am happy to update today with a solution which removes this bug from DeluxeMenus.
Much thanks goes to @Disorbs as he has done tons of testing specific to this problem and is the reason this update exists today.
I hope that everyone can update as soon as possible because he has went as far as joining servers that run the plugin to confirm the issue exists on those servers.
I am sorry if this problem has caused anyone issues in the past but it should no longer be an issue going forward.