Having trouble with pledges
I have now reported this bug here; https://issues.civicrm.org/jira/browse/CRM-17651

The bug only shows up when using price fields for a contribution page. There are good reasons for using price sets, however, and there is no reason I can see not to allow pledges when using the price set functionality. 

If you have any fixes or workarounds that allow me to still use the price sets, please let me know!