Interesting – the HSBC website www.hsbc.co.uk appears to only deliver content in GZip. Any user agent trying to get to it that does not support GZip (through the Accept-Encoding header) will just get nothing from the server (it holds the connection but delivers nothing).
If, for whatever reason, you’re trying to get to the HSBC website with a simpler (ie. non-mainstream) browser this might be why. I’ve been getting very slow and funky (ie. corrupt) images in Firefox for a while – wonder if it’s related?