Version:            (using KDE 4.2.2)
OS:                Linux
Installed from:    Ubuntu Packages

When using Konqueror as a file manager with a left/right split view, further splitting of the left side of the split view into a top/bottom split view causes the right side of the left/right split view to be automatically removed.  This results in a top/bottom split view.  I'm able to reproduce this reliably:

1) Using any existing or new Konqueror instance, split the view left/right.
2) Make the left side of the split current, and split it top/bottom.  The right side of the original left/right split disappears, leaving only the top/bottom split view from what was the left side of a left/right split.

Interestingly, this problem does not occur when top/bottom splitting the right side of the original left/right split.  It only occurs when performing a top/bottom split of the left side.

This problem is recursive to any split depth.  That is, split the view to any level and in any combination.  Then split the left side of any left/right split, and that particular split becomes a top/bottom split and remove the right side of the left/right split.