If the kernel changes, device support is likely to change as well. If the current kernel string "uname -a" is different than the one the dev.tar was generated for, rebuild the cache.
Assign this bug to Lin, Tong
Fixed in http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=ac62f06e09be6d8b00ce1a0c7b8d90f776792471