There is something in the [hijack] section of config.ini that is incorrect for that version of Hijack.
As the Hijack options change, you will need to edit old entries in config.ini to prevent the error. For example, Mark recently removed the features for doing the Flancedoor visual name substitutions, so those need to be removed if you've got them in place.
You also might have a corrupted config.ini that's over-sized because of the repeating favorites bug.
Take a look at your config.ini and see what's incorrect about it.
Loren, something for the Hijack FAQ, perhaps?