Comodo Dragon 17.1 will not allow access to web mail

I have Comodo Dragon 17.1 on three computers. I have been unable to access these webmails sign in pages:
Juno, Yahoo and Gmail. I do not have any other web mail services so I do not know if they are
working or not. I can access these three web mail sign in pages successfully using Google Chrome and IE9.
I can’t understand why Dragon won’t allow access. I get messages like this:

This webpage is not available
The webpage at Yahoo might be temporarily down or it may have moved permanently to a new web address.
Error 108 (net::ERR_ADDRESS_INVALID): Unknown error.

Thank you for your assistance

UPDATE: I now have same problem with fully updated IE, Firefox and Chrome. All three computers
have Win 7 32 bit - and fully updated Comodo Firewall. I have cleared history and caches on all
browsers, reset wireless router, and ran fully updated Anti-malware and Anti-virus scans with clean results.

Topic can be closed. I found that updated Comodo Firewall had changed setting in Firewall Behavior
on all three computers. I temporarily changed setting from Safe Mode to Training Mode and was able
to log in to all three web mail servers. I then changed setting back to Safe Mode and all three still work
from all computers. Hope this helps someone else - I did not change the setting originally on any of the
computers - I am sure that a Comodo Firewall update did. Perhaps this can be cross referenced in the Firewall forum. Thanks to all who read my post.