Maybe it's not a slip-up, but one scene Dylan (Drew Barrymore), has a flashback of when she dated Seamus McGrady and mentions that she sent him to jail, 8 years ago. So 2003...minus 8 years...equals...I assume it's 1995.

Here's where I think they slipped up, during the flashback we have young Dylan and young Seamus driving along, okay so why does it seem like it's the late 80's? They're rocking out to Livin' on a Prayer, and they both look like washed out 80's metalheads. I don't know, it just doesn't make any sense to me...