Thanks for your answer - yes I'm aware of region-specific limitations.
Just to be sure, I've downloaded and compared last official fimrware (2.03b03 aka 2.03 final) located on Hungary FTP and our FTP location (Czech Dlink server). The binary firmware inside zip file is exactly the same, although their name differs.
hungary - DLINK_DNS320.2.03b03(2.13.0618.2012)(BETA).zip
czech - DNS-320_fw_revA_2-03B03_all_en_20120919.zip
Even 2.03 official firmware downloaded from "global" ftp.dlink.com is the same. Filename "dns320_FW_203" (not zipped, without filename extension).
So wish me luck, hope I won't brick my DNS-320 flashing 2.04b01
