Why the tranparancy slider is not avaialble when I bring in few layers from one category from Layer Catalog?

Hi,

 

I'm not sure if this is the right forum for this question on Layer Catalog, but I have an issue which looks to be bug.

 

The tranparancy slider is not avaialble when I bring in few layers from one category from Layer Catalog but when I bring in layers from 2 different category on Layer Catalog I get the tranparancy setting slider. is this a bug?

 

Thanks,

 

Dibya