My host was having an unrelated issue (error 421: too many logged in users) as a result of incorrect connections not being terminated… they said it wasn’t me… but anyway - I tried publishing locally and FTP’ing using Forklift and the files uploaded without any error, multiple times…
Unfortunately, something still appears to be broken somewhere, either in Foundation, Rapidweaver, or Total CMS, or Stacks… which I’ll try to get to the bottom of…