Scanrand works ok (for me at least) on BT2 install.
When you use scanrand you can also open and run an instance of tcpdump to see the output in a different way than scanrand returns.
Try something like
# scanrand -c -b1M -t 3000 192.168.0-63.1-254:80
-c check spoofing of icmp -b1M send packets at 1Meg -t 3000 time for scanrand to wait for any response before exiting.
When setting up targets you need to use ranges and commas and not CIDR Network mask. Normally it would look like 192.168.0.0/18 and of course we are looking at port 80. Of course the following is the same in tcpdump.
# tcpdump -s 1500 -i eth0 -w scanrand.tcpdump net 192.168.0.0/18
I hope that provided some help to someone