i use a Linksys Router with Tomato Firmware. I assign a fixed IP to the DNS-323 (Static IP), and of course, i name it.
So i can access the DNS using 2 different way : \\ipadressofthenas\Volume_1 (or 2)
or \\mynasname\Volume_1 (or 2)
Some router are not very good with DNS name, so access it using the Fixed IP you assign will work.
Other thing, if you are using access restriction on the DNS (username and Password). Try to use the same username and Passord in Windows, and on the NAS. Sometime, Windows made some weird response. Having the same username and password prevent these time of weird response.
use the naming convention 8.3 (8 char max... but don't use the .3 ..)