A fresh installation of Kubuntu 8.04 beta in a VirtualBox VM with Firefox 3.0 beta added produces the same result, except that the choice "open with Firefox 3.0b4" is replaced with "open with <empty entry>".
A fresh installation of Kubuntu 8.04 beta in a VirtualBox VM with Firefox 3.0 beta added produces the same result, except that the choice "open with Firefox 3.0b4" is replaced with "open with <empty entry>".