Well, I found another way around my hostnames on the lan issue which avoids any messing about that might break things. Basically, instead of just trying to ssh or ping the hostname, I've found (On my setup.) that if I put .home on the end of the hostname, it works!

I've often noticed the .home bit on my network but not thought much of it. What prompted me to try it was a bit of googling which brought up this old post and by comparing resolv.conf on my N900 and on my SimplyMepis desktop. My desktop's file contains: The domain home bit caught my eye and to my delight, hostname.home worked!