Here's a link to the file I created. I take no responsibility if you brick your camera using it.
http://home.comcast.net/~jeremyfr/davinci.tar.gz
This is only to enable english in 5.1.6, do not use this file for any other firmware
The new value you have to change in 5.1.6 is 8a 30 dd e5 38 a0 9d e5,
You'll change it to the be 8a 30 dd e5 01 a0 a0 e3
That's it and you have english menus and english day of the week in OSD.
You don't have to use a patch, you just have to follow the directions of this thread with the new value that Bellavitus provided, I did it last night, quite easy, takes 10 minutes.
You have to use the directions in the first post to get English back, however the hex value changed slightly in 5.1.6, Bellavitus posted the new value about 10 posts back from this one.
Or you can use chrome browser and let it translate the page for you, that works quite well as well.
I believe on mine it did, but that's easy enough to fix, I just had to check the DHCP box again after rebooting it from the update. as for the admin password I use default on mine anyways so couldn't tell you on that part.
I made the change to the string that bellusvita posted and it worked fine on both my cameras, figured what the hell I know how to bring em back from the dead if it didn't work lol. So yes the string bellusvita posted for 5.1.6 does work. Lastly if you want 5.1.6 its up on the European website...