OpenELEC the embedded version of XBMC has been updated to 4.2 Beta 4. This new build has XBMC Gotham 13.2 RC1, an updated kernel, fixes for Live TV and updated firmware for the Raspberry Pi. This build includes a new SD Card driver that fixes many of the issues with the old driver and should improve the performance and reliability of the Raspberry Pi with OpenELEC. By default the new drive is not enabled but you can do it manually. Going forward it will become the default driver.
This build includes a new MMC/SDCard driver, which is disabled by default.
This is expected to become the default sdcard driver in the future. It should avoid some of the issues of the old driver, like polling with interrupts disabled, and could improve performance and avoid interfering with other drivers (e.g. USB or LIRC).
You can choose the new driver with adding bcm2708.bcm2835_mmc=1 to cmdline.txt. To edit your cmdline.txt run the following commands and reboot after the change:
mount -o remount,rw /flash
You can get the new version from openelec.tv