Josh Hartnett as Sherriff Eben Oleson in '30 Days of Night'

The 29-year-old struggled to film scenes in the vampire picture after contracting the "kissing disease".

He says, "I was falling apart because I had glandular fever, otherwise known as the kissing disease. You're supposed to have it at 14, so apparently I haven't kissed enough people."

And the actor was further plagued by a handful of injuries while filming.

He adds, "I broke a knuckle, ruptured a blood vessel in my eye and kept getting beat up with cuts and bruises. It was a trying first month."

Hartnett and Johansson dated for a year after meeting on the set of movie The Black Dahlia , but split in November last year (06).

Source: WENN