Help please! I am tryign to ice a c cake with Sylvia Weinstock's BC Icing and I am having problems!

I made the BC earlier today and refrigerated it. I brought it back to room temperature and am now trying to use it but it keeps separating. It isn't smooth at all! Anyone knwo how I can bring it back to correct consistency?

Also, can I decorate with this icing? It seems too thin.

Any help would be appreciated!!!

never mind...i experimented and re-whipped the icing and it went back to it's original consistency - in case anyone is interested