stoutfellow | Cross-posting

I've set up my Dreamwidth account so that, if I post something there directly, it will cross-post to LiveJournal. Apparently, though, this does not happen if I post via a client (Semagic, in my case). I've read the instructions on how to post to multiple accounts from Semagic, but apparently, since I have the same username in both places, this doesn't work either. Does anyone know how to get this to work? (I really much prefer using Semagic to direct posting.)