What plugin are you currently using? I wanted to use WPArticleFetch but had errors during the setup.. Now I am using Wp-O-matic.. currently doing well with but have to manually fetch articles since I don't have cron jobs on my hosting plan and I am still having problems with running web crons.. my blog is currently a semi-autoblog since i had to manually fetch articles.. What plugin are you using and can you give your reviews on each and which is better so I can try it?
setacronjob.................................you can go there..............and set your cron .............
I run a service for my autobloggers that helps them setup cronjobs easy : http://www.cronwatch.com Also consider my BlogSense (http://www.blogsense-wp.com) if you ever decide to go high end pay route.
As far as i remember, Wp-o-Matic has an in-built cron which processes the feeds automatically. Also search in google for cleanDuplicatePost. Its a nice wordpress plugin, but is not included in the plugins database. It helps autobloggers to automatically delete duplicate posts.