What error message are you receiving when attempting to connect?
On Saturday, my PS2 froze when I was logging on. After that, I received a POL – 120088 (or something similar) error when trying to log back on. It turns out that one of my POL files was corrupted, and could not be updated. I reinstalled POL, and it resolved the issue.
Not sure if you experiencing something similar, but wanted to let you know just incase.