I haven't had much luck with Linaro Linux 3.1 and 3.3. However, version 3.2 released in January (https://launchpad.net/linux-linaro/+milestone/3.2-2012.01) seems to boot up and shut down well. I know it isn't a prebuilt image, but right now manually compiling the kernel with omap2plus_defconfig configuration seems to be only way.