Perspectives uses the standard HTTP protocol to query network notary servers. However, some of these notary servers are unable to listen on the standard HTTP port (port 80) and instead listen on port 8080. While most firewalls and proxies should allow this traffic, some may not. You can contact your network administrator to find out whether Perspectives traffic is likely being dropped by a proxy or firewall.
NO. When Perspectives is unable to reach the notary servers, it does not receive the data necessary to distinguish between a valid and an invalid certificate. Accepting a certificate without notary validation can be dangerous, because it may be that an attacker is intentionally dropping your notary queries.