I haven't had experience enough to say BUT I have read on here that some freeze their cakes for about 15 to 20 minutes and the crumbs then CAN'T move. 
Hopefully others that are experienced will be here to help you soon,
Susie
When I finally got the knack for making my crumb coat very thin, and my second coat much thicker-so crumbs can't show through, it seemed that my cakes came out much nicer. I don't know if that statement helps you at all, but you might want to check your consistancy of icing. 
I still have problems with crumbs. I'll have to try a thinner crumb coat. I find with mine though that it will look fine, no crumbs.. then the next day it's like the crumbs bleed through ?? Not sure why or how they do that.. but it seems the longer my cake sits, the more crumbs start showing through.
When I finally got the knack for making my crumb coat very thin, and my second coat much thicker-so crumbs can't show through, it seemed that my cakes came out much nicer. I don't know if that statement helps you at all, but you might want to check your consistancy of icing.
ditto to this...sometimes I even have to put a 3rd coat on. I freeze for a few mins in between and that also seems to help
crumb coat very thin, and my second coat much thicker-so crumbs can't show through, .
This is what I do and have no problems at all. No freezing first is necessary for me but if I ever had the problem I would not hesitate to chunk it in the freezer for a few minutes.
Quote by @%username% on %date%
%body%