Yes the details pane should resize to the space given to it. I have not been able to reproduce this behavior on Windows 2000 SP4. I set it up with 1024x768 resolution, configured the panes like you have them, and all panes including details are always sized correctly (with the down button on the vertical scroll bar always positioned at the bottom of the pane).
There are some differences about your screen shot that I noticed. The background of the start menu and other menus appears to be white rather than the default grey, and the system appears to be using Sans Serif for the GUI font rather than the default Tahoma. Are you running a non-English language version of Windows? Have any other customizations from the defaults been made?
Can you ZIP and post or send to
support@kinook.com
1) a .urd with an item containing the text shown in your screenshot
2) an export of the registry key HKEY_CURRENT_USER\Software\Kinook Software\Ultra Recall (using regedit.exe)