Blocked pop-up exceptions

The operating platform that I am using is Windows Vista Home Premium, Service Pack 2; 32 bit.
The security software is the currently up-to-date version of Norton Internet Security.

The problem that I have encountered is with the Options > Content > Block pop-up windows Exceptions system. A listed exception, my health care provider’s web site, is not allowed even though the Ice Dragon 26.0.0.2 browser indicates that it is an allowed exception. Even when the browser is shut down and restarted the obstacle persists. I have also disabled the Options > Privacy > Clear All History > Site Preferences removal option and restarted the browser - all to no avail. Deleting the entire Block pop-up windows option does not solve the problem either. The Block pop-up exceptions list does work with the Foxfire 27.0.1 browser using the same operating and security systems.
- Mark Lee