Files/layers won't snap to the beginning of the comp

Question

I went from AE CS3 to CS5.  In CS3, whatever item I had on a layer would snap to the beginning of the comp.  But in CS5, I notice that many things (like video clips and image sequences) will not snap to the beginning of the comp, although other things (like text layers and individual images) will.  Am I doing something wrong?  Is this a known bug?  Thanks.

Answer 1

Thanks so much for your reply.  But that is not exactly what I was asking.  When I shift/click and drag a video clip (that is already on its layer in the comp) to the beginning of comp, it does not snap to the first frame when I do it in CS5, but it does in CS3 (and always has in all the versions before that as well).  Sorry if I did not initially ask my question clearly enough.
And actually, now that I try it again with various layers, I realize that none of them are snapping to the first frame when I shift/click and drag them, although they do snap to the current time indicator and to other clips on other layers. (In my original post, I had mentioned that some layers, like text layers were snapping, but it appears that I was incorrect, because as I try now, they are not snapping to the first frame either)