one idea, why this could work on 3 but not 4 toons may be:
- perhaps you have keybinding like 'shift + slave-key' bound to another action, so that it dosen't trigger the makro, which is only bound to 'slave-key'
- you used some keys as your slave-keys, which can't be used in kombination with all modifiers, like F1-F12, Numpad (see: http://www.dual-boxing.com/wiki/inde...ld_of_Warcraft ).

Additionaly you could post/pm me your macros and i perhaps am able to find the problem