The domains are looked up through a two step process. The first step is finding the registrar, name servers and whois server. Once the whois server is known a second connection is made to the whois server to extract the actual ownership information. In addition to the whois lookups the software also finds the IP the domain is pointing to.
Use the Lookup menu option list to start the lookups. Please be aware that high speed lookups are not a good idea. Please see the following knowledge base article for details on this.
To prevent getting black listed by various registrars we have set very conservative lookups speeds by default. You can reconfigure this for different whois servers.
Right click on a domain name and select the Data extraction setup > Whois Server menu option to change the number of connections and interval (see screen shot below). By default, for most whois servers the setting is 1 connection. You should increase this and / or set a lower connection interval.

This specifies the total number of simultaneous connections that will be made to the whois server by the software. Set it to an optimum number based on your bandwidth, CPU resources and the connection count allowed by the registrar. Please note that some whois servers will block access if you make too many simultaneous connections.
The software employs an interval timer to initiate new connections. You can adjust the timer interval using this parameter.
If you find too may connection errors come back to the connection settings box and adjust these settings.
Most registrars have made changes to their whois servers to prevent very high speed whois access. It is very important that you set the connection interval to higher value (15 seconds and above). Also make sure that the number of simultaneous connections is set to 1 or 2.
If you continuously make a large number of requests, registrars may ban your IP address.