> it works on ie 7-8 if you use mootools 1.2.5 but not if you use 1.2.1
The Fiddle uses 1.2.1. That was a purposeful emulation of your older
environment.
http://jsfiddle.net/kgBcs/2/show/light/
Please demonstrate how the above Fiddle requires 1.2.5 to work on IE.
Note only the 'Add' link has been altered to use the workaround.
-- S.
