I've tried all of the WP plug-ins at one point or another and found that all of them have their own quirks depending on the feed, the version of the plug-in and the version of WP itself.
I think the phase of the moon affects it too but don't have any proof.
Thats why I would recommend
Blogs Automater. It's not free but does have a fully functional trial that will allow you to run three blogs.