cell splitting problem

[Unknown]

I have a problem passaging some chick fibroblast (OU2) cells. When I use
the recommended mix of trypsin/edta, the cells come off as a single sheet 
that does not want to split up, even if the cells are not yet confluent 
(though with lots of intercell connections). Anyone ever experienced this 
as a problem with any other cells, and overcome it? If so, how?

thanks for any help you can give

michael baron