hmm odd... I just downloaded the client so it should be up to date, and I'm pretty sure I've left that pop up running for a while with no results. Maybe it's some sort of glitch and it's not connecting correctly to check. That wouldn't make sense either though, since the patch checker window always pops up and runs its progress bars, saying it's up to date.
Sometimes it will actually begin to start but I just get a small black "elsword" window, followed by a large one. And then it closes and nothing else happens. Wonder what that could mean.