I just upgrade my XO-1 to 10.1.2 and now have issues with extremely slow write speeds on the SDHC card, i.e. the write speed is so slow that doing a simple scp or rsync will freeze and basically crash the machine as it will become completly unresponsive. Copying stuff to the internal memory still works fine and reading from the SDHC card also seems to be normal, but writing is extremely slow. dmesg doesn't output anything suspicious.
Does anybody have an idea what could cause this?