It's not just you. The clouds have been gone in the Linden viewers since V2.8. I presume this code base has found it's way into Phoenix. The clouds were removed by Oz Linden, apparently on his own initiative. All we are left with are the two dimensional clouds painted on the windlight backdrop. Perhaps no one told him that Second Life is a 3D world. If you would like to have them back see: https://jira.secondlife.com/browse/VWR-26597?