Please follow kraada's directions too - the more information we have the better. If you can include a specific example of a hand number where you should have seen the mucked cards along with the hand history file and the logs that would really help.
We are currently investigating the cause of this issue and how best to resolve it. If you would like automated notification when a fix is available, please create a support ticket and we will make sure you are notified when a fix is available.