The Westpac mobile banking website used to work well on my Lumia 710/Windows Phone 7.8 until very recently.

However they seem to have re-launched with a new "mobile optimised" site. The result for me on my device is the site now only serves the Desktop version, even if the "Mobile" version link is clicked. So now the usability is quite poor.

Is this specific to Windows phone i.e. Westpac cannot be bothered testing Windows Phone/IE9? Or is it a more generic issue re sites detecting screen sizes correctly.