It's something more fundamental broken in Mail.app on Ventura PB 6. If you drag an image attachment, for example, to a Finder folder, it drags some corrupt file with the extension .inet or something similar. Eventually it works after a few tries. This was working in earlier betas and, of course, every other past OS.
I feel like Apple has some people randomly punching keys to code at their company lately. It's very frustrating that both hiring quality software engineers and having proper quality control have simultaneously taken a nosedive. I realize this is Beta, but it's unacceptable to be breaking old functionality at this point in the beta cycle.
Wishing for OSX Snow Leopard.