In Linq to SQL the following works by issuing a second query, in Linq to Entities it does not (and this sucks):
Shortcut sh = db.Shortcuts.First();
int count = sh.Redirects.Where( r => r.ocurred < dt).Count();
You have to do the following instead:
int count = db.Redirects.Where( r => r.shortid == sh.id && r.ocurred < dt).Count();