Hi,
I have the same problem, I had to reset mine a while ago. Until yesterday I had 2x Windows7, 1x WindowsXP & 1x MacBook Pro able to access the contents of the hard disks in my DNS-343. However since the reset I can't access the configuration or downloads page (using its IP address directly in a browser) or check any information on on the DNS-343 ie what firmware is on it. From any of the 4 computers on any browser.
I was able to access it from my MacBook until yesterday. I just upgraded to MountainLion OS & that's dropped the connection. Now when I try to connect from it to the NAS I can either connect as a GUEST or Registered User (but what is that as far as the DNS-343 is concerned? I'm sure there are none set up at the DNS-343...) but no logins work, admin/[blank], admin/admin, admin/password, [blank]/[blank]. So it will show me the DNS-343 & the shared folders I've created on it, but I'm not allowed to browse into any of the folders within the shares. I presume this is to do with the ML OS upgrade, but I can't look at any info on the DNS-343 due to the login not working.
Any / all help / suggestions appreciated to help me be able to access the configuration, perform firmware upgrades & access the contents from my MacBook.
Thanks
Ob