When you log in a character you should see a line in chat to the effect of "You are already in channel DarqUI_sdfsdf." If not, open the browser setup page in the window manager and manually add your private channel, then restart the game.
As a side note, I would move the utility out of DarqUI_v3 and into the \UI\ folder. This way, if you do decide to delete and reinstall DarqUI you won't be clobbering the utility. If your DarqUI Notify app is in DarqUI_v3 I would move it into \UI\ also.
