DEAN: I know this is a stupid question, but why can’t you just talk to him?
LANE: Because yesterday he called to say that they were still looking for a rehearsal space and, uh, that he’d call when he had more news. So now I have to wait until he calls about the band – and in between, I call and hang up on him. Pathetic.
Lane has been calling Dave and hanging up when he answers, just so she can hear his voice. She and Dave are in regular contact even though the band has apparently gone on a break while they look for a suitable rehearsal space (he phoned her just the day before). However, lovesick Lane is still calling him multiple times a day.
Dean finds this behaviour ridiculous, and then he discovers Rory used to hang up on him before they were dating. I’m not sure how she got his number when they’d only spoken a few times, maybe Dean gave her his number straight away (which would surely be a clue he liked her?). Also, why doesn’t Dean remember someone ringing him all the time and then hanging up two years ago?