Look's like we could point out that it is a H/W release C1 problem.
I upgraded my device several times with the 1.08 firmware. I noticed, that the temperature was shown in C and later in F. Unfortunately, I don't remember from where I got the firmware

. Nevertheless there seems to be different version of 1.08 firmware (interesting from the configuration management point of view...).
I could identify 3 dlink ftp sever hosting the 1.08 firmware:
ftp://ftp.dlink.com/Multimedia/dns323/Firmware/dns323_firmware_108.zip
ftp://ftp.dlink.ru/pub/NAS/DNS-323/Firmware/DNS-323_C1_FW_v1.08
ftp://ftp.dlink.se/Products/dns-products/dns-323/drivers_firmware/DNS-323_FW_1.08.zip
Has anyone experiences with those files? I tested the .com file, can't connect to the Swedish server and want to test the Russian file during the next days...