Disabling wp-cron stops blog from loading

I have been using Mailpress for a subscription service. I was following the instructions to disable wp-cron and use the cron that is included with Mailpress to send out the batches. I have the cron jobs figured out and have enabled wp-cron to run twice per hour, but when I edited wp-config and disabled wp-cron from running in the background, the blog will not load. This includes the front end and back end of the blog. Nothing loads. Removing the edit allows the blog to load properly.

I would appreciate any advice you can give.