Problem setting firefox default browser KDE 4.3.1

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#1

I’ve just updated to latest kde 4.3.1 from factory repo.
After this when I’m trying to open any link at kopete or plasma widgets i get an error dialor:

KDEInit cannot start «!/usr/bin/firefox».:
Could not find '!/usr/bin/firefox' executable.

Changing default browser back to Konqueror makes the trick and link are opened by Konqueror.

Any ideas how to make it start firefox?