Hikvision 5.1.6 Firmware

I have uploaded digicap.dav 5.1.6 (i think chinese version) -md5check f9b9d55c5ad22a7551d1a53cf5b654ac.
I try to patch with hack explained here: http://www.ipcamtalk.com/showthread...2-firmware-on-China-region-cameras-to-English
1) enable telnet
2) login
3) export davinci.tar.gz (md5 cca923b08ff431593abd951ca6d04ec1)
4) decompress davinci (md5 1c671a7b17d8a6a80ef8a50ba01d64e3)
4) with hex editor don't find "8a 30 dd e5 38 a0 9d e5 53 90 c4 e5 14 90 9d e5" but only "38 a0 9d e5" so change it in "01 a0 a0 e3"
5) new davinci have md5
4906e0f5b0a23c219713f3556e615200
6) compress it (md5 a7a2bbc413d1e791b40eebfccb4a1294)
6) upload it and reboot

the web ui remain in chinese! which firmware have you used?
 
found the problem....
the replace hex digit are:
5.1.2
8a 30 dd e5 38 a0 9d e5 53 90 c4 e5 14 90 9d e5
8a 30 dd e5 01 a0 a0 e3 53 90 c4 e5 14 90 9d e5


5.1.6
8A 30 DD E5 38 A0 9D E5 20 30 8D E5 53 B0 C4 E5
8A 30 DD E5 01 A0 A0 E3 20 30 8D E5 53 B0 C4 E5
 
I have succesfully upgraded my HIK 2332 camera with the characters CCRR in the serial number and multi language menus from version 5.0.2 to version 5.1.6 build 140612 with multi language menus as well.
However please note that the characters in the serial number now have changed to CCWR. Why is this happening and what does it mean?

The camera was purchased from Bulgaria and I have a suspicion that CCRR is Russian Region targeted HIKs and when they are upgraded they are changed to International version (English version?).
Also after the upgrade the telnet does not work even if it is enabled in the camera interface. I am getting the error "connection failed". Has anyone encountered this problem?

Does anyone else have similar experiences with respect to upgrading camera firmware and changing the region code?