bonnie222,
I have to agree with johnpoz. You have something going on with your DNS configuration. Have you checked your DNS settings to make sure you have a DNS server configured? Can you successfully look up A records for sites like www.pfsense.org and files00.netgate.com. If you can't do A record lookups you certainly aren't going to be able to do SRV record lookups.
There is an option under 'System -> General Setup -> DNS Server Settings' that allows your ISP DHCP settings to override the local DNS server settings. If you are using DHCP from your ISP and using their DNS servers make sure this is checked. This should not be unchecked unless you have your own DNS servers, you want to use different DNS servers (like google), or your ISP doesn't provide DNS via DHCP. If the box is unchecked you have to manually configure DNS servers.
If your box has Internet access to google's DNS servers you can test by using 8.8.8.8 as a DNS Server, uncheck 'DNS Server Override" and check the "Disable DNS Forwarder'. This will skip using the pfSense box for DNS and go directly to Google's DNS server. If this works then either your ISP isn't providing a DNS server via DHCP and you need to configure a DNS server manually or your own DNS server is filtering what you are allowed to resolve.
Hope this helps.