2.5.18
[System]

New text editor function for magnifying glass by long-pressing text will show highlighted words in preview pane
Optimisation to further improve interactive gestures in the text editor mode (will not display when the input box is empty when you press the cursor and optimise double-click selection criteria)
Fix volume key wake causes abnormal operations
Optimise text editor copy operations

[Phone]

Fix FC for three-way party calling in some cases (CDMA)
Fix in some cases leaving the call interface and attempting to return to call will not work and also lead to abnormal sensor feedback
Fix in some cases automatic IP prefix number is not displayed in the call interface
Fix service center number with area code, call list cannot be identified
Fix some models to make an emergency call in the emergency dialing interface
Fix clicking the call button to dial, ending call returns to desktop
Repair (CDMA) the green return to call bar shows the incorrect call time duration
Optimisation of displaying the back part of the name on the call interface when the name is too long
Optimisation of numbers before the cursor are deleted by long pressing on the delete key in the dial-up interface
Optimisation of the green return to call bar does not display call time until the call starts

[Lock screen, Status bar & Notifications]

Added quick entry to Calendar functions by opening status bar area and pressing on the date (left of screen) will directly open Calendar
Optimisation of screenshot notification, will no longer display more icons to the right of the status bar
Fix lock screen display delay issues
Added quick access to System Settings in status bar

[Desktop]

Added new app switching animation transitions

[Themes]

Optimisation, MIUI v4 no longer supports the old theme packages
Optimisation - updated default theme preview
Optimisation - Support wallpaper scroll type, e.g. By Theme, Centre, Left or Right
Fix in some cases the list of available local themes shows duplicated items
Fix ringtone preview process, switching to another item / page does not stop the previous ringtone preview audio
Fix being unable to apply default theme status bar customisation
Fix problem changing theme, long press the power button the pop-up dialogue will not allow you to restart phone for theme changes to take effect

[Contacts]

Fix cannot find partial match when searching for contact using Chinese input
Add support to set the Caller ID
Optimised contact details page to view contact details, such as name is too long and scrolls

[Messaging]

Unable to repair new message search for contact number
Fix memory leaks result in some cases of the application slowing down or FC errors

[Camera]

Optimize UI details of photo when being used by other applications
Fix FC caused by flashlight setting error in shutter zero delay mode
Fix wrong status of flashlight button caused by switching application after selecting a specific scene
Fix description error of the image size (should be 800 000 pixels) caused by shutter zero delay
Fix description error of the image size (should be 800 000 pixels) caused by shutter zero delay

[Music]

Fix playing song does not save bug
Fix problem with 4x4 widget does not sometimes refresh

[Gallery]

Added support to directly set lock screen wallpaper from application
Optimisation to avoid constant decoding of 0byte files

[Settings]

Optimise the mute volume control panel volume intensity to indicate new setting

[Backup Manager]

Add support to setup automatic local backups (See Settings menu for more info)
Fix in some cases restoring desktop items cannot correctly display third-party widget / icons

[File Explorer]

Added search function (See menu)
Optimise load speed of file classification summary menu
Fix after all files are selected in the list, the menu still shows incorrect select all option

[Download Manager]

Optimise download waiting information - show if waiting for Wi-Fi connection or if the file is to be downloaded automatically
Fix data connection cannot resume correctly
Fix problems pushing file from PC to download, download complete status shows incorrectly
Fix problem downloading multiple files (batch)in some cases causes FC error

[Browser]

Optimise the address bar search functionality by splitting it away from the address menu
Optimise tab switching in order to not block the bottom of the toolbar
Optimise video playback in the browser control panel
Fix night reading mode, open a new page will show display flashing

[Alarm Clock]

Fix edit mode cross-slip still shows problems
Fix in some cases new alarm clock does not automatically enable
Fix Stopwatch interface issues with HTC ONE-X

What doesn't work?

-Camcorder doesn't work
-FM radio
-minor bugs

------------------------------------------------------------------------------------

MIUI 2.5.18 更新日志

【系统】
优化 改进了文字编辑的一系列交互细节（包括当输入框为空时点击不会出现游标，优化双击选择判定等）
优化 文本编辑选择、复制操作
修复 音量键唤醒引发操作异常的问题

【电话】
优化 通话界面过长名字显示改为截取后段部分
优化 拨号界面修改号码时，长按删除键只删除光标前号码
优化 通话未接通时，通话绿条不显示计时
修复 (CDMA)某些情况下三方通话导致FC的问题
修复 某些情况下离开通话界面，由于感应器反馈异常导致无法返回通话的问题
修复 某些情况下自动加IP前缀的号码在通话界面不显示的问题
修复 拨号列表中带区号的服务号码无法被识别的问题
修复 某些机型在紧急拨号界面无法拨打紧急电话的问题
修复 点击呼叫按钮拨号，结束通话后回到桌面的问题
修复 (CDMA)通话绿条的通话时间显示不正确的问题

【联系人】
新增 支持设置来电大头贴（编辑联系人->编辑头像）
优化 进入详情页查看联系人，如名字过长会滚动显示
修复 某些情况下，搜索联系人无法匹配名字的问题

【短信】
修复 新建短信时无法用号码搜索联系人的问题
修复 因内存泄漏导致某些情况下短信变慢或FC的问题

【锁屏、状态栏、通知栏】
新增 通知栏顶部增加前往日历（点击左上角日期区域）和设置（单页模式下点击“开关”标签页右上角）的入口
优化 截屏通知不再显示右侧多余图标
修复 锁屏显示延迟的问题

【桌面】
新增 全新APP切换动画，和APP内界面切换的动画

【主题】
优化 更新默认主题的预览图
优化 壁纸支持裁剪
修复 某些情况下列表页主题重复显示的问题
修复 铃声试听过程中，切换到其他页面，播放仍然不停止的问题
修复 不能单独应用默认主题状态栏模块的问题
修复 更换主题后，长按电源键弹窗的样式重启后才能生效的问题

【相机】
优化 被其他应用调用时，拍照结果界面细节
修复 快门零延时模式下，闪光灯设置错误导致卡死的问题
修复 选择特定场景后，切换应用导致闪光灯按钮状态错误的问题
修复 快门零延时模式下，对图像尺寸描述错误的问题（应为80万像素）
修复 被其他应用调用时，拍照结果页仍然可以点击显示对焦框的问题

【图库】
新增 支持设置锁屏壁纸
修复 不断解码大小为0字节图片的问题

【音乐】
优化 使用线控时控制当前打开的音乐播放器，而不是调起系统音乐播放器
修复 播放记录不保存的问题
修复 4x4 桌面小工具有时不刷新的问题

【备份】
新增 支持设置自动本地备份（见菜单->设置）
修复 某些情况下恢复桌面无法正确显示第三方程序桌面小工具的问题

【设置】
优化 静音时音量控制面板音量的示意方式

【文件管理器】
新增 搜索功能（菜单中呼出）
优化 提升了分类页面的载入速度
修复 全选列表中的文件后，更多选项中依然有全选的问题

【下载管理】
优化 下载时关闭数据，下载状态显示不正确的问题
修复 数据连接时无法断点续传的问题
修复 从PC推送的下载，完成后不显示下载完成状态的问题
修复 某些情况下，批量下载导致FC的问题

【浏览器】
优化 将地址栏中搜索功能拆分出来，切换搜索引擎更方便
优化 标签切换时不遮挡底部工具条
优化 浏览器内视频播放的控制面板
修复 夜间模式下打开新页面会闪动的问题

【闹钟】
修复 编辑模式下横滑，没有退出编辑模式的问题
修复 某些情况下新建闹钟不自动启用的问题
修复 One X 机型秒表界面错位的问题

不可使用的功能

摄像机

FM收音机