Actually it happened to me today, I joined a tournament 1 minute before late registration ended, sat at the table with 1500 chips, blinds were at 100/200, so I had little more than 5 BB. Got unlucky, no good cards came to my hand and before I knew it I was almost with no stack at all. As a previous member said, entering 10-15 minutes after the start of the tournament isn't much of an issue, however entering too close to the end of late reg. might become a really issue, because blinds are too high and it's hard to keep up, so be very careful with it.