I received the reply below from an iTunes Support person, but I'm not convinced that it is not a problem originating with Apple, as I find it hard to believe that so many users are suddenly experiencing this issue and it could be related to "web acceleration or firewall software." I haven't made any configuration changes to my system and all of a sudden as of 10/30 have had this trouble.
Has anybody else contact support and received a response similar to this (below) ?
+"I am very sorry, but this is not an issued with the iTunes Store.+
+The error you describe may be caused by the presence of web acceleration or firewall software. While the iTunes Store is unable to provide technical support, I can recommend that you either test your connection to the iTunes Store without the presence of this software or configure your system to allow access to the iTunes Store's address.+
+For assistance in configuring your firewall or accelerator software, you may need to contact its manufacturer or your Internet Service Provider. When contacting support representatives, it may be useful to have the following information:+
+"Well Known" TCP and UDP Ports Used By Apple Software Products+
+
http://support.apple.com/kb/TS1629+
+iTunes for Windows: Connection Issues when using Internet Filters, Accelerators , or Firewalls+
+
http://support.apple.com/kb/TS1379+
+You may also find a resolution in one of the following articles:+
+iTunes for Mac: Possible iTunes Store errors+
+
http://support.apple.com/kb/HT1412+
+iTunes for Windows: Possible iTunes Store errors+
+
http://support.apple.com/kb/TS1424+
+If you use Windows, this article can help you pinpoint any software conflict that might be causing this error:+
+Using MSCONFIG to troubleshoot conflicts in Windows+
+
http://support.apple.com/kb/HT1275+
+Apple Discussions are another source of information about iTunes, where everyone from new users to professionals can interact and share their knowledge and experiences. You may find another user with the same operating system or ISP that may be able to help resolve this issue. You can find the iTunes discussions group at:+
+
http://discussions.info.apple.com/itunes+"
Funny thing is, if they'd referred to this discussion thread, they would have seen multiple users reporting this same problem.