Microsoft has just released latest update 7.1.1 for their Windows Phone SDK, with something new:
1. Add new emulator, development tool, compile config and documentation for 256MB RAM devices
2. Add new language and localization ( See HERE for full list)
3. Improve memory usage and management in XNA
Yup, that's it. And here are some bugs in this update:
1. After you add an entry to the application manifest to opt out of 256-MB devices, with Windows Phone SDK 7.1.1 Update an application can still run on a 256-MB version of Windows Phone Emulator or on Windows Phone. To opt out of 256-MB devices, you also need to add a REQUIREMENTS section and a REQUIREMENT element with a Name attribute value ID_REQ_MEMORY_90 to the WMAppManifest.xml file. This way, an application that you have opted out of running on a 256-MB device cannot be downloaded from Marketplace.
2. Generic background agents are not supported on 256-MB devices, or on the 256-MB emulator. If you design your application to add a PeriodicTask task or a ResourceIntensiveTask task using background agents, an InvalidOperationException exception occurs. This exception means that the maximum number of background agents for the device has been reached. To ensure that your application runs on 256-MB devices and on the 256-MB emulator, make sure you design your application to handle these exceptions.
To uninstall this update
: remove the KB2669191 update in Windows Phone Emulator, Windows Phone SDK 7.1 Assemblies, Windows Phone SDK 7.1 Add-in for Visual Studio 2010 and Hotfix for Windows Phone SDK 7.1 ENU