Also thinking about it... I think you cannot add a ScriptManager to a skin? Have you tried this, because that's a similar scenario (technology-wise) as the one with master pages, and for that they produced a ScriptManagerProxy which you add to your controls for easy access to ScriptManager (which you would add to a master page) functionalities without having the actual ScriptManager present in your control.

That's good to know.

I've made it work completly with all the scenarios I wanted to test by adding it with web.config changes only (that was my goal).

I've tried this scenario adding it from a module, you can find if there is already a ScriptManager, and if not add it... but unfortunatly the control events happen to late in the hierarchy to attach the ScriptManager in at the right event (it works if you do it with Page Pre_Init event, and events after that are too late as I've seen - wish someone would correct me here ).

My advice will be to do it all via web.config because you don't brake any boundaries of funcationality like you do via skin, and you don't do it directly in the page either. I am working on tutorials which will describe this as some best practice I am advising (at least until DNN guys integrate it correctly).

I meant outside of module development, so core changes needed... I think it's best practice when doing changes to DNN core to do them minimally, so I've focused my efforts to web.config only (+ copy 2 dlls to bin directory).

If you want to use update panel scenarios, of couse you need to add update panel to your module... but that's ok.