always need two attempts to run online update

Hi

when I run online update, opensuse 12.3, I get a 'server inaccessible' message, but it works OK when I click 'Retry'. This happens for each repository. If I try later in the same session after this, it will connect at the first attempt.

The same happens for Thunderbird email but not in a web browser.

This happens with both wireless and wired connections, so I guess it is a system setting but I don't know what. Any advice gratefully received.

Thanks very much.