Opera 7.20 for Windows beta 2 -> beta 1 changelog:

* General * 
- Support for opening protocols without // (magnet:, aim:) in external program - see "File > Preferences > Programs and paths" 
- Print selection enabled - prints only text for now 
- Memory fixes 
- GIF animation fixes 
- Improved image display speed 
- BiDi fixes 
- ISINDEX fixes 
* User interface * 
- Possible to undo/redo (Ctrl Z/Y) marking of mail as read/unread, delete/undelete mail, and closing of browser windows. Limit: 100. (Known issue: Deleted mail is marked as read, and undoing delete will not go back to Unread status.) 
- Ctrl+Alt+Z available as shortcut for reopening most recently closed page 
- New "Closed" menu under the "Window" menu on the main menu bar listing the 100 last closed windows 
- Fix for unreliable menu highlighting 
- Fix for entering special characters into edit fields while at the same time supporting various shortcuts. Differentiate between the special AltGr key and the left Control+Alt key combo, so that it is now possible to press AltGr+some key for special characters, but also Alt+Control+same key to produce a shortcut instead 
- Performance/lockup fixes 
- Drag and drop improvements 
- Fix for launching external source viewer using quotes 
- Fixes to URL handling in Notes 
- Fixes to the Wand 
- Other tweaks/fixes 
* M2 * 
- Support for showing only mail belonging to specified account - dropdown in Hotlist, or available from "Mail > Show account" 
- Support for account categories. Set category under "General" tab in account properties ("Mail > Manage accounts.." dialog). Also available from dropdown in Hotlist 
- Support for hiding mail in custom views from other views (properties, "Filter" tab) 
- Disable account dropdown from "Mail > Show account" 
- Regexp filter support 
- Improvements to authentication and auto selection of authentication methods; support for POP3 CAPA 
- IMAP fixes