mootools/mootools-core — Issue #2266: Calling setOpacity with null does not remove the style 
Author: jpdery
Created: 2012-01-31 14:40:32+00:00
State: open

As demonstrated in :

http://jsfiddle.net/d2XnX/1/

Setting the opacity to null does not remove the opacity style. Arian says it has something to do with the value being parsed with parseFloat.

Thanks