speed change and multi clips

I have some clips that I would like to make into a multi clip but i get this error message:

"Unable to make multiclip. One of the items you have selected has a speed change."

I have tried to create an independent clip but it doesn't seem to make any difference.

BTW the clips all came from one large (38 gig) parent clip and I suspect that how I created my sub clips has something to do with my problem. I had to do the time changes because this all old 16mm film transfers that are out of sync with a soundtrack that I am using.