Some of our users in Singapore are having problems posting to their blogs. It appears to be a problem with their ISP SingNet. We are in contact with SingNet to resolve the issue.
In the meantime, take a look at the workarounds suggested by a blogger and report the problem to SingNet's tech support.
Update, 05/18 10PM: We have been working with SingNet engineers to resolve the problem and we believe SingNet users should be able to use Blogger normally again. If you are a SingNet blogger and are experiencing trouble posting, please update this discussion.