firefox3 gets stuck/freezing for 30 seconds every 30 seconds

[O. Hartmann]

Since a week now my firefox3 got stuck and freezing for 30 seconds 
(approx.) every 30 seconds. I'm running a SMP box with FreeBSD 
8.0-CURRENT/amd64, OS is most recent.

I also recompiled firefox3, dbus, libX11 and xcb (maybe senseless since 
I do not know what causes the freezing/hungs), but without success. By 
the way, perl-5.10 is installed and every port has been recompiled 
depending on perl. So ... I'm floating like a dead man in the water. 
What can I do?

Regards,
Oliver