With two Sheets bound to a class to display separate view and edit page layouts the AttachmentSelector fails to set the uploaded file.
Sheet 1 has the 'edit' property set for the XWiki.SheetDescriptorClass object.
Sheet 2 has the 'view' property set for the XWiki.SheetDescriptorClass object.
It sends a redirect with a docAction=inline which doesn't display the correct layout.
If I remove the 'edit' XWiki.SheetDescriptorClass object then the attachment selector works, but the correct 'view' Sheet is not used.
I worked around the default XAR import by doing the following:
I checked in the xaction=postUpload section of the XWiki.AttachmentSelector macro if the docAction was 'inline' and I changed it to 'edit' instead.
This then seems to work fine with both Sheets and the XWiki.SheetDescriptorClass set for both as appropriate.