Internet Explorer Mobile:One-Column Layout
Fig 1. One Column Layout 
I had a complaint from a customer of mine, that the Internet Explorer Mobile(Windows Mobile 5.0)
does not render their HTML reports in a tabular form. At first, I was wondering if they found a defect in
our custom HTML exporting feature.
Then I realize what happened.
We're using a sequence of TABLE,TR and TD tags
to have our HTML content rendered into a tabular form. Some of the users accidentally had switched on
the One Column feature of the Mobile Internet Explorer.
This layout forces the Mobile Internet Explorer to render all content in a single column
without horizontal scrolling.
Fig.2: Default layout 
Links
IE Mobile Team Weblog
Wikipedia for IE Mobile