$ cap staging deploy
  * executing `staging'
    triggering start callbacks for `deploy'
  * executing `deploy'
  * executing `deploy:update'
 ** transaction: start
  * executing `deploy:update_code'
  * executing "svn checkout -q  -r392 svn+ssh://myproject.com/repos/
myproject /var/www/apps/dev.myproject.com/releases/20071016185844 &&
(echo 392 > /var/www/apps/dev.myproject.com/releases/20071016185844/
REVISION)"
    servers: ["myproject.com"]
    [myproject.com] executing command
 ** [err] Host key verification failed.
 ** [err] svn: Connection closed unexpectedly
    command finished
*** [deploy:update_code] rolling back
  * executing "rm -rf /var/www/apps/dev.myproject.com/releases/
20071016185844; true"
    servers: ["myproject.com"]
    [myproject.com] executing command
    command finished
command "svn checkout -q  -r392 svn+ssh://myproject.com/repos/
myproject /var/www/apps/dev.myproject.com/releases/20071016185844 &&
(echo 392 > /var/www/apps/dev.myproject.com/releases/20071016185844/
REVISION)" failed on myproject.com

So it seems there's a problem with my ssh login, but

1) I'm not telling it to use an ssh key, it seems like it should be
prompting me for a password, so I tried adding ssh_options[:keys] =
%w(/Users/[myusername]/.ssh/id_rsa), but got the same error.  Next I
tried deleting my authorized_keys entry on the remote server, after
which I did get prompted for a password twice, but the same error
comes up.

2) I have no problem logging in to ssh and running the checkout
command from the console

What am I missing?

Thanks.