Yes, the AssetPickers.js file is registered twice, this is the cause uf the problem.
We have found a preliminal work around, which works for the time being:
In the file AssetPickers.js in .../12/LAYOUTS/1033 we replace
var APD_AssetConfigGlobalObjectDictionary=new Object;
var APD_AssetConfigGlobalObjectDictionary=(typeof(APD_AssetConfigGlobalObjectDictionary) =="undefined")?new Object:APD_AssetConfigGlobalObjectDictionary;