McAfee Web Gateway blocking requests?

I'm trying to use SoapUI for testing REST services, but my company uses McAfee Web Gateway which is a kind of proxy and it appears to be blocking all my requests. I've talked to our IT about it and they think it is because SoapUI isn't sending the authorization info along with the requests. In SoapUI preferences I added the correct information to Proxy Settings and pushed in the button in the icon bar to "Apply proxy defined in global preferences", but it doesn't seem to work. Any ideas?