Linq and nullable varchar column

Question

Hello,

is there any posibillity to turn off Linq replacing empty strings with null on nullable varchar columns?

I could set the column to NOT NULL, but the scheme is used by other application too, so I would like to avoid that. I've tried to set column not nullable in DBML, but then I get "System.Data.Linq.ChangeConflictException: Raw was not found, or was changed." error.