problem with http requests and fopen()

I have moved my wordpress install successfully from one server to another and everything is working fine apart from parts of the backend admin panel.

RSS feeds, incoming links and Google XML Sitemaps are all having problems communicating with external servers. Here are a few examples of error messages:

RSS Error: WP HTTP Error: Could not open handle for fopen() to http://blogsearch.google.com/blogsearch_feeds?scoring=d&ie=utf-8&num=10&output=rss&partner=wordpress&q=link:http://thekemnalacademiestrust.org/

RSS Error: WP HTTP Error: Could not open handle for fopen() to http://ww.wp.xz.cn/news/feed/

RSS Error: WP HTTP Error: Could not open handle for fopen() to http://planet.ww.wp.xz.cn/feed/

Ping Test

Trying to ping: http://www.google.com/webmasters/sitemaps/ping?sitemap=http%3A%2F%2Fthekemnalacademiestrust.org%2Fsitemap.xml.gz. The sections below should give you an idea whats going on.
Errors, Warnings, Notices:
WP_DEBUG was set to false somewhere before. You might not see all debug information until you remove this declaration!

Notice: Use of undefined constant manual_save – assumed ‘manual_save’ in W:\Webhosting\tkat\wp-content\plugins\page-lists-plus\page-lists-plus.php on line 499

Notice: Undefined index: manual_save in W:\Webhosting\tkat\wp-content\plugins\page-lists-plus\page-lists-plus.php on line 499

Notice: WP HTTP API Web Request failed: Could not open handle for fopen() to http://www.google.com/webmasters/sitemaps/ping?sitemap=http%3A%2F%2Fthekemnalacademiestrust.org%2Fsitemap.xml.gz in W:\Webhosting\tkat\wp-content\plugins\google-sitemap-generator\sitemap-core.php on line 4745

Please help! Everything was fine before… Is this something to do with the wordpress install or is the new server fussy?

Cheers