Thanks but your link is broken. Here is the link for the 551 model:
[150529] ZE551ML_WW_V2.18.40.12-Release Note
And here is the list of fixes. Sadly, none of the bugs I'm experiencing appear to have been fixed. (Update: I found two bugs that I got working for the first time, so that is good news).
【Version】
V2.18.40.12_20150529
【Model Name】
ZenFone2 (ZE551ML)
【Release Date】
2015/06/04
【Release Note】
Use Google Search Widget on Default Home Screen (WW SKU)
Improve Calendar App stability
Fix Calling screen flow issue when make calls by both SIM1 and SIM2
Improve Telephony stability
Fix the Do not disturb mode issue that "Allow only priority interruption" would be back to default settings after reboot
Fix MyASUS stability issue
ASUS Power Saver
- Provide variety of power saving mode for users to choose
- Auto change to Ultra saving mode when low battery
- Add Auto switch mode
Add YahooAuction (TWSKU)
Fixed 3rd party app issue.
Return OK when setting parameters during picture encoding.
Do not vibrate when android mode is incall.
Update FW
Fixed video gamma incorrect.
Improve the image quality.
Improve service stability
Improve modem stability from crash
Improve signal bar stability
Force output to be primary output when using BT_SCO.
Fixed system will reboot when connecting to VPN
Increase multiPartition Number to 256
Fix Download yahoo mail attachment issue when using ASUS Browser
Fix several Browser issues
Optimize Miracast connection UX flow
Fix the issues of wallpaper installation failure through Dropbox
Improve Music App stability
Fix several issues in Settings
ASUS Support UI improvement
Improve Sound recorder stability
System UI: Improve the SIM icon in system UI after FOTA MR6
Increase 3dB gain for receiver.
Improve Flip Cover function
Using HW encode for 4G SKU.
Correction privacy mode can not start a single hand mode
Fixed difficult to lift the screen fixed function
Fixed SIM settings issue
Fixed browser unusual problem