If you have downloaded it please stop using sync and mass-downloading entries for a while.
The protocol has been disabled because of this right now.
Version 18.104.22.168 is OK(because it does not have this feature, as well as all other features in the new one are ok).
The problem is that due to large amount of Semagic users (in comparison with other clients also having these archiving features) LiveJournal serveres cannot handle such value of simultaneous downloads.
More info here:
According to the latest stats at sourceforge( which updates with 2 days delay), there were 2,657 downloads in the first day. That means that almost all viewers of ljwin32_sema and lj_nifty (where it was also posted about cool search feature) downloaded the client specifically to use its new feature and began to download their whole journals from the beginning. Post-per-day count at LJ is currently about 200,000, while (2000 users in one day)*(from 1000 up to 3000) posts = from 10 to 30 times higher.
200,000/24=8,300 posts per hour. This means that 3-5 users downloading journals from the beginning in one hour can double LJ load. 500,000 active users /365 days=1,400. This means that with this load (like 5-6 Oct) it will take a year for all users to download their journals.