Have been getting some error messages whilst using Firefox. When clicking on a link, using Bookmarks or my Home Page (Google) I sometimes get an error message saying "the server cannot be located". Hitting the "retry" button sometimes works, as does going to another site from Bookmarks. Have done some research on the Firefox help pages, and there is a suggestion that this might be caused by problems with an ISP's Domain Name Server. Anyone experiencing similar problems since switching to Sky?