I have flashed CM11 M6 on my tf300t recently. It runs perfectly with the pad itself. However, when I connect the pad to the dock/keyboard, it keeps reporting "com.android.systemui" stop running error until I remove the dock.
I flashed CM11 from the latest stock rom (JB 4.2 bootloader 10.6.1.27.5) and followed the instructions on the wiki page carefully. I also tried to wipe data, cache, dalvik, and even system partitions and re-flash it with the same issue...
BTW, tried the latest released M7 with the same issue, but M5 works fine for me.
I'm not sure if there is some new bug since M6, or I did anything wrong. Any help will be really appreciated.