I have been able to get console redirection and virtual media working with Epiphany 2.29.6 and Iceweasel (Firefox) 3.5.6 after upgrading the DRAC 5 to the 1.51 firmware. I installed default-jre and icedtea6-plugin to get a Java JRE and used the Java plug-in to test. (default-jre installed the OpenJDK JRE.) I haven't tested the Firefox plug-in. I can now get rid of the copy of Firefox 2.0 that I kept around for working with the DRAC 5s.
Console redirection via a Java plug-in was added in 1.40, and Firefox 3.0 support was added in 1.45.
The DRAC 5's SSH host key changed after installing the 1.51 firmware.