Here we are in 2012 and I have the same problem, but my Mac AE has no Control-Shift-D shortcut and I see no command to split a clip in two from the CTI. My goal is to use the first 10 and last 10 seconds of a 30 second clip but skip the middle.
Nevermind, I see now. I have "Split Layer" under Edit when the CTI is located in a composition layer.
And it's command-shift-d on a Mac.
Also, this kind of task is much more suited to a video editing program, if you plan to do a lot of it.
My ctrl+shift+D isnt working because I have an app called Ding talk and when I try to click ctrl+shift+D
only that app apperas instead of clips being splitted.PLEASE HELP:(