Anyone else seeing unlikely compile errors when running DoubleClick’s API version 2 for the first time? Namely this error, originating from one of the Studio classes:
5007: An ActionScript file must have at least one externally visible definition.
If so, our developer Jamie and Paul Feneht from Google discovered that a folder of extraneous classes must be deleted first before version 2 will compile correctly.
The folder path is:
\Users\[you]\AppData\Local\Adobe\Flash CS5\en_US\Configuration\Classes\com\google
Remove it completely and the new Studio API classes should work. Though this issue isn’t documented yet, the DoubleClick Studio version 2 API documentation is otherwise very thorough, at http://studio.doubleclick.net/docs/sdk/flash/as3/en/.

For Mac, the folder path is:
Users/[you]/Library/Application Support/Adobe/Flash CS5/en_US/Configuration/Classes/com/google
If you are using Flash CS5.5, go into that folder instead of the CS5 in the path.
Also, “Library” and “Classes” may be hidden folders, so option-double click when opening the parent folder in Finder to see them. Or use Terminal, which will show hidden folders.