There is nothing special about my case that I can detect - I'm not even certain that it's because the partition is encrypted, it may be because it contains an ext2 rather than vfat partition, or it may be connected with the device mapper. I have another SD card to play with so when I find the time I'll try a few things to see if I can pin the problem down. At least I have a workaround for the time being.

On an unrelated issue - I often find myself coping /etc/resolv.conf from the native Maemo filesystem to the Easy Debian filesystem so that I have domain resolution available for debian apps. Would it make sense to automate this?

Thanks for your enthusiasm and prompt responses!