Had this problem and thought it was serious.....After reading through posts, I decided to check this misfire situation that had began......Popped off the engine cover and started motor at night......All 6 plug wires were fried and the spark was jumping around everywhere......Replaced them and she runs great.....Thought I would post this so someone could save time and nerves worrying about tranny problems......Good luck and maybe this is your only issue......

Hmm, I have a similar sparking problem on my 3rd plug. But I just changed my wires. My car does shake a bit at idle though.

This was happening to me... I thought my tranny was toast until I replaced my spark plugs and surprise surprise, no more shudder!