If you experience a "salesforce.com refused to connect" error, it is a Salesforce redirection error. This means that if you were in the middle of creating records, they were already created e.g Bulk Donation Entry, Receipt or ATS downloading.
To resolve this, you can try to disable Clickjack Protection.
1. Click Setup | Security Controls | Session Settings.
2. Disable each of the following settings:
Enable clickjack protection for customer Visualforce pages with standard headers
Enable clickjack protection for customer Visualforce pages with headers disabled