Well, I had the same situation after upgrading to 10.6 (as if the 10.6 installation wasn't already hard enough). I went poking around Google and I found a forum on the D-Link website with people like us with the same problem.
In two of those forums, I saw some had upgraded their DNS-323 firmware from 1.06/1.07 to 1.08 (beta). Mind you, 1.08 is a BETA and that some people on the D-Link forum had problems after upgrading the firmware. Specifically, issues concerning automatic formats of HDs after the upgrade and others ( I can't remember them all).
I downloaded the 1.08 firmware and upgraded the firmware. However, to ensure that my HDs were not formatted or corrupted by the new firmware, I shut down the DNS-323 and took out the HDs. Then I uploaded the firmware without the HDs. after the firmware upload was successful, I shut down the server, and put the HDs back into the server. The BETA firmware definitely worked for me and I was able to mount my file share.
The only thing that didn't work for me was the mail feature. I put all the correct settings into the mail section to give me daily reports and logs of the server. However, when I tried to send a test message, the server's web administration site timed out on me for five minutes. Although this does not affect the mounted file share (I was able to read and write to my server during the timeout), i cannot get daily logs of my server's activity.