[OpenBSD 5.1] No ssh login to SE/30 - too little computing power?

Hi there!

I've installed OpenBSD 5.1 to my Macintosh SE/30. I can ssh from this 
machine to other hosts but I can't ssh to this machine. I already tried 
to rule out common issues (e.g. by disabling DNS) and tried to use least 
cost MACs with compression and ciphers turned off. Still, I'm unable to 
log in.
As far as I can interpret the log files, it seems that the key exchange 
negotiation takes too long, leading to a timeout. This is why I was 
under the impression that too little computing power was the reason - 
any key "stuff" usually takes ages.

This is the client log
http://pastebin.com/PxC12xbx

and this is the sshd log
http://pastebin.com/11GR9Eqx

Unfortunately, I'm no expert in SSH apart from the "usual" settings in 
sshd, so most likely I'm missing something. I just can't figure out what 
it is.

Regards
   Steffen