Off and on with different distros I have noticed a strange behavior in Kmail and/or Firefox. Clicking on a link in a Kmail email will open Firefox (as it should), but with two identical tabs. That is, it opens the same page twice, simultaneously, in seperate tabs.
XiniX, over at the KDE Community forums, steered me toward the solution. In this file:
In the “General” subsection I changed
and suddenly, no more double tabs!
XiniX… you da man! Thanks!