Same here.
What I did was to start dropbear ssh on a second port.
Just add to the dropbear line -p 22 -p 2222 or something
This is what I have in my post-boot
/usr/sbin/dropbear -b /mnt/ramfs/local/welcome.msg -p 22 -p 55909
and in post-firewall
iptables -A INPUT -p tcp --syn --dport 2222 -j ACCEPT
If you use firm 1.8xx
the command should be something like
iptables -I INPUT 2 -p tcp --syn --dport 2222 -j ACCEPT
to avoid the last drop