Users cannot get Blackthorne to connect to eBay. Item submissions, refreshes, etc., result in an endless loop of authorization screens or simply does not return data.
One of the known causes of this issue are incorrect Proxy Settings in Windows. Your correct proxy settings will depend upon how you connect to the internet. Your ISP should provide you with proxy settings if you need them.
One scenario that causes this problem is specifying that you use a proxy server without providing the proxy server address. This condition has been known to set by some spyware or internet accelerator programs.
Other known caused include:
a firewall or a spyware program is preventing the connection
incomplete or corrupt Windows system files
eBay Blackthorne on your AOL Blocked list
deleted or invalid registry entries corrupting your Internet connection.
If you are a DirecWay satellite user, using a DW4000 modem, another possible solution can be found in the KnowledgeBase article KCON002 - DirecWay Satellite user connection problems.
If your internet connection does not use a proxy server, then you should not have one set in your internet options.
Click on Start and select Control Panel.
From the Control Panel, choose Internet Options.
On the Internet Options window, select the Connections tab.
Click the LAN Settings button. The Local Area Network (LAN) Settings window will appear.

If the "Use a proxy server for your lan..." box is checked and an address and port is not specified in the Proxy Server group box (as shown above), then you should uncheck the "Use a proxy server for your lan..." box and the "Bypass proxy server for local addresses" box.
Click OK to save and exit.
To make sure you have the latest updates, you should go to Help|Support|1. Prerequisites and click the Windows Update button, then follow the prompts to make sure you have all the latest required updates.
It has also been reported by an XP user, that uninstalling and reinstalling Windows XP Service Pack 2 fixes the problem.
If you are an AOL user, please ensure that eBay Blackthorne is not on your blocked list.
Because eB must perform many interactions with eBay "under the covers", it may trigger spyware programs such as AdSubtract or Webroot SpySweeper to identify it as spyware and stop the interactions. Try disabling your spyware program to see if it fixes the problem. If so, you may be able to customize your spyware program to allow eB access to the internet.
Option^Explicit Software Solutions has a free utility program called WinSockFix that might restore your Internet connection. You can learn more about WinSockFix from the following link:
http://www.softpedia.com/get/Tweak/Network-Tweak/WinSockFix.shtml
All versions of eBay Blackthorne.