samba browsing doesn't adapt dynamically to network changes

Binary package hint: gvfs-backends

Very similar to Bug #191547 (most of this description is copied from there). But this time it is about hardy and gvfs.

Samba browsing works like a charm after login. gvfs sees all samba workgroups and servers:

$ gvfs-ls smb:///
E-WARE
MUNKACSOPORT
VIRTUAL

But after switching between wired and wireless networks, gvfs no longer sees any samba workgroups or shares.

$ gvfs-ls smb:///
[no output]

After some digging with wireshark, I noticed that the problem is that gvfs sends the NMB name lookup requests to the wrong broadcast address.
For example:
1. Let the wired network be: 192.168.5.0/24 (broadcast 192.168.5.255)
2. Let the wireless network be: 192.168.6.0/24 (broadcast 192.168.6.255)
Let's suppose that the wired connection was active when I started my gnome session. Then after switching to the wireless connection gvfs still keeps sending NMB name lookup queries to 192.168.5.255 which is WRONG.

Workaround:
$ killall gvfsd-smb-browse

Putting the above line in some if-up/if-down script makes the problem go away.

$ dpkg -l | grep gvfs| cat
ii gvfs 0.2.3-0ubuntu4 userspace virtual filesystem - server
ii gvfs-backends 0.2.3-0ubuntu4 userspace virtual filesystem - backends
ii gvfs-bin 0.2.3-0ubuntu4 userspace virtual filesystem - binaries
ii gvfs-fuse 0.2.3-0ubuntu4 userspace virtual filesystem - fuse server
ii libgvfscommon0 0.2.3-0ubuntu4 userspace virtual filesystem - library

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=8.04
DISTRIB_CODENAME=hardy
DISTRIB_DESCRIPTION="Ubuntu 8.04"