There's a new installer available if you go to http://earth.google.com/download-earth.html (It's not yet available via Check-for-updates, but that should change early this week)
It is v4.0.1657 (Windows), v4.0.1658 (Mac), and v4.0.1660 (Linux).
It has the following fixes:
Changes From Version 4.0.1565 -----------------------------
- Language selection in client: Tools->Options then the "General" tab
- Restore missing Search/Places/Layers panes if the user chose to hide them in version 3.0
- Scroll wheel now defaults to "zoom in" for "wheel up". The setting can be reversed in Tools->Options then the "Navigation" tab
- More reliable reading and writing of kmz files on systems with non-ascii usernames
- Fixed imported terrain for SketchUp occasionally showing 'divots'
- Client now remembers the checked status of all layers between restarts
- Improved memory management, client does not require as much memory
- Automatic setting of memory cache based on machine RAM, improves performance and prevents flickering overlays
- Fixed warnings about Software Emulation and DirectX on Mac and PC systems
Developer Notes:
- Fixed <Update> tag operation
- Fixed deletion of local kmz file when linked to by network link
- Fixed style information being lost upon restart of client (for some styles that were shared across a folder)
- Using <Update> on LineString coordinates now replaces all coordinates rather than appends
- Fixed network link occasionally going into fast continuous refresh