jQuery Mobile website is strangely magnified in Opera Mobile 10 despite 100% zoom level

I've developed a mobile website based on jQuery Mobile. Everything works on my own Windows Mobile device with Opera Mobile 10, but a customer of mine always sees the page magnified.

I thought that he might have a zoom setting >100% in Opera Mobile, but he claims that this is definitely not the case.

The same problem also occurs on the jQuery Mobile test site ( http://jquerymobile.com/test/ ) . Here's a screenshot of the site as displayed on my customer's device:

enter image description here

Any idea what might be going wrong here? I was unable to reproduce this problem on my own device or in an emulator.

My customer's device is a HTC HD2 runing Windows Mobile 6.5 and Opera 10.

Thanks,

Adrian

Solution

I'll just paste the answer by David Storey which was made for this on Opera Dev forums. It is not specifically about the 100% issue, but there might be similar issues related to the viewport tag issue, for people getting across it.

Opera Mobile assumes that any document with a mobile specific doctype, such as XHTML Mobile Profile or XHTML Basic are designed and optimised for mobile, while documents with a regular doctype are not optimised for mobile generally. Thus if there is a desktop doctype the overview mode is enabled, which you can control with the viewport meta element. If there is a mobile doctype the overview mode is disabled and a regular 1:1 viewport is used.

There were some bugs in the viewport meta element support in Opera Mobile. They should be fixed in the latest version.