> svn://<my address at dyndns>:3690/svn_eclipse What is the IP of the NAS on your LAN? it has to work at svn:// 192.168.1.105/ first, before you can get to it from the net via your DynDNS url.
Once you verified that you can connect from a PC on your LAN... check your internet device eg cable/DSL router (login as admin @ 192.168.1.1)? You may need to create a 'Service' for 'SVN'=>3960-3960, often under 'Gaming'. (example IPs)