I used iJournal for about a week, and it absolutely rocked - hard enough to make me switch from what I was using.
Then I changed my password to something long (over 10 characters) and hard to break. I can still post to my LJ from Flickr, XJournal, and LJ itself - but not from iJournal. Every time I try to log in, it asks me for my password.
And then I give up, and use another client, and everything is fine.
Does iJournal only transmit passwords up to a certain length? This is the only thing I can think off, off the top of my head. iJournal is so superior to everything else that I'd really like to go back to using it.