It only affects Gmail. I have tested other HTTP, FTP and HTTPS websites and downloading is fine, at the exact same time the problem is affecting a Gmail attachment download.
The symptoms include both:
- High waiting time, before the download starts (on the order of 30 seconds); AND
- Very slow download transfer speeds (on the order of 1kbps)
It's a very strange problem, and I didn't find any recent issues relating to Google Australia. The account works fine at another site with a different ISP, so it's either a computer configuration or ISP - I lean to the latter.