You could try going back to LW 4 & see if it connects. Lime Wire » Download Out-Of-Date Installers and If LW 4 Will Not Connect (click on the blue link). I do not see anything in your specifics that should prevent you connecting. However there was another recent using with problems connecting who used the same model modem.

Might be worth deleting your LW prefs folder again if you do go back to LW 4.