I've just rolled back to beta 3 so that the shared clipboard from RDM's remote desktop sessions goes through ClipboardFusion. I think this was the line in the log generated by attempting to copy from RDM.

##_##BFClipboard:ClipboardContainsFallbackDONOTUSE:199##_##-##_##Clipboard format is unknown., [System.Exception]##_##-

Note that the clipboard sharing still works. Both the local and remote machines have access to each other's clipboard, it's just CF that refuses to touch the entries.