Version:           1.9 (using KDE KDE 3.5.0)
Installed from:    Gentoo Packages
Compiler:          gcc version 3.4.4 (Gentoo 3.4.4-r1, ssp-3.4.4-1.0, pie-8.7.8) 
OS:                Linux

When an HTML email contains absolutely-positioned elements (ie a DIV with CSS position:absolute;top:100px), the email header appears to be included in the height calculation. Because of this, elements don't line up properly. 

How to reproduce: 
Create an HTML email with some elements positioned absolutely in pixels from the top of the screen. The position of the body begins *after* the header, but absolutely positioned elements are positioned from the top of the window, which means that the calculation *includes* the header. 

Expected Behavior: 
All HTML elements (either absolutely or normally positioned) should use the same frame of reference. 

Example: 
Email with absolutely-positioned elements in Kmail: 
http://blendinteractive.com/kmailbug/kmail_html.png

The same email in Thunderbird: 
http://blendinteractive.com/kmailbug/kmail_html2.png

The same email in KMail using Brief headers. Notice that the offset is reduced, indicating that the elements are absolutely positioned from the top of the window rather than the top of the content.
http://blendinteractive.com/kmailbug/kmail_html3.png