Version:            (using Devel)
OS:                Linux
Installed from:    Compiled sources

Long text lines in message boxes are not wrapped by default resulting in one long line that is shorted by replacing the middle part of the text with "...".
A better solution would be to put <p> tags around the text which make Qt to wrap the text according to the message boxes size.

An example is kdebase/workspace/kwin/kcmkwin/kwincompositing/main.cpp (as of rev 866903) which contains the following KMessageBox call if the composite stuff fails to work.

KMessageBox::sorry( this, i18n(
 "Failed to activate desktop effects using the given "
 "configuration options. Settings will be reverted to their previous values.\n\n"
 "Check your X configuration. You may also consider changing advanced options, "
 "especially changing the compositing type." ));

The actual message box shows the text as follows:
"Failed to activate desktop effects using the given ...Settings will be reverted to their previous values.
Check your X configuration. You may also conside...tions, especially changing the compositing type."

It requires the user to enlarge the window to read the whole text.

I suggest to check the whole source tree with some script for KMessageBox calls with long lines. Then, either the text can be placed in <p>..</p> tags or some manual editing can be performed. In this step, "\n\n" could be replaced by a closing and opening <p> tag.