I have found file sharing to be broken on install since 10.04.

install ubuntu 10.0X on 2 machines on same network.

Try this on both machines:

open file browser.
right click on any folder.
choose "sharing options".
check "share this directory"
click "create share" button
you will be prompted to install file sharing. do it.
afterwards you will be prompted to logout/login. do it.
reboot both machines if you want to.

now browse the network and try to open a share on the other machine.
you get a "failed to retreive shares message"

That's it. Doesn't work out of the box.
I found a fix, I can't remember what it is offhand, you have to install or remove a wins server or something, I can refer to my notes if anyone is interested. Problem is that the fix now breaks network printing.

Very bad for beginners or anyone trying to move off of Windows. This is the second release in a row that has this problem... who do you talk to?

slightly frustrated... I can fix it, but this is the type of thing that windows user and newbies complain about. Bad PR.