Version:           3.0.0 (using KDE KDE 3.1.3)
Installed from:    RedHat RPMs
OS:          Linux

To reproduce bug:

Set IDE to Ideal mode.

Open two files. File1 and File2.

Select File2 tab to edit.

tabs should be as follows:
 _________  ___________
/ O File1 \// O File 2\\
-----------             ----------------------------

// File2
// yadayada

Where "0" is the kdev icon.

Close File1 without selecting the File1 tab i.e., hover above the "O" in the File1 tab, let it change to "X" and click the "X".

Although the "X" gets pressed down, the tab does not close and you have select the File1 tab to close it.