Version: (using KDE 4.1.3) OS: Linux Installed from: Ubuntu Packages When i use middle-click to close actual tab in konqueror, just get Error window: Protocol not supported. I mean, this is not expected behaviour.
Mh, this is because, the changes of that option aren't reflected in the same Konqueror instance (you have to restart it). So, middle clicking a tab would do the default action (open the URL you have in the clipboard in that tab; if you don't have anything in the clipboard, it will say "Protocol not supported")((Look at bug 157753)). You may change this bug report to ask for changes in that options (or all Konqueror options) to be reflected inmediatly in that Konqueror instance/window. (I support that)
Bug 163533 may be related to this.
Confirming as for KDE 4.5 beta 2, Konqueror has to be restarted for this option to take effect.
Cannot reproduce this in KDE 4.7 branch. If I check the "Middle-click on tab to close it" check box under Settings->Configure Konqueror->General and middle click on the tab, then the tab is closed immediately. I do not have to restart Konqueror for my configuration change to take effect. I can only replicate the behavior described here when the aforementioned option is not checked. Closing this ticket as WORKSFORME. Feel free to reopen it if the issue persists for you in the most recent version of KDE, v4.7.2 as of this response.