virtualbox.org

In 3.2.2 I no longer get a guest system to talk to another guest when using Bridged interfaces.
Both are accessible from the host and other computers on my network and the guests can access all network resources. However, Neither guest can talk to each other.

There is no firewall on my Mac host or the Guests (2 x Ubuntu 10.04 and 1 Windows 2003 Server)

This used to work in 3.1.8 and earlier for over a year.

These kinds of problems that are reproducible should be reported to bugtracker. You will need to setup an account there as it is on a different system.
It would also help if you can post the ticket number here so other can see the progress, add information, or see the final results.