Hello,

first I must say that I have read all the KNewsticker threads with similar problems but none of those helped me.

When I click news on the KNewsTicker it launches a new window of firefox with two tabs, both has the same url which is what i clicked.

I have set to kde's file associations and component chooser the command correctly as firefox %u. I have also tried every option from the tabbed preferences from firefox, i have also the plugin for more options.

Urls works fine from every other program except KNewsTicker. Im frustrated.

Sorry for my English.

I was using konqueror instead as my associated app. I changed it and didn't see what you are seeing. My command is the same: firefox %u
You might try changing it to: firefox --url %u

You may also want to enter in the firefox address bar:
about:config
and apply the filter "browser.tabs" and check your settings.

I tried to cut and paste my values but it didn't work. Part of what I got was funny:
<window id="config"
xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
width="750"
height="500"
onunload="onConfigUnload();"
onload="onConfigLoad();">