if ssh works, can you create a tarball and download the tarball via the web?
tar czf whatever.tgz *
its possible that sftp is failing because of a message being printed in the .profile/.bashrc -- I know rsync has a problem with that at times.
if ssh works from the remote server, you could do something like:
rsync user@firstserver
ublic_html/ localdir/
or
ssh user@firstserver "cd directorytogoto;tar cf - *" | tar xf -
or if you can put the tarball in a web accessible place, from remote server:
wget
http://firstserver.com/tarball.tgz
You might have a version mismatch which is causing sftp & securecrt to conflict, i.e. maybe the server is older and doesn't support ssh2 and one or the other refuses to use ssh2.
Many different possible problems that I can think of -- one of the above should get you working.