Example:

for(i =- 1; i < 2; i++)

$("#test"+i).hide(i,function(){ alert("callback " + i + " fired"); });

Result:

i = -1 -> div "#test-1" is hidden -> callback fired

i = 0 -> div "#test0" is hidden -> callback NOT fired

i = 1 -> div "#test1" is hidden -> callback fired

I am building an application with variable and configurable speeds. And I was assuming that a speed of 0 would disable the animations, and it does, but it breaks the callback functionality. I would expect to see the callback fired regardless of the speed setting, since it's basically an event that tells you it is done showing the element.