I'm pretty much out of bright ideas at this stage, so we might have to wait for someone else to jump on in to help.
The fact that neither linux machine can access windows says to me it's a windows firewall thing or a windows password thing, either way having no experience with Vista's setup I can't really help. I can only suggest you go and poke around in your firewall settings and see if you can find a place to enable exceptions for file and print sharing on your network.
The only other thing I can think of that it might be worth checking is if all machines are using the same workgroup/domain.
It really shouldn't make any difference as long as you've set up permissions on the shared drives and files correctly (chmod 757 dirname -R) using a terminal.
However, if you want to make sure - the Feisty machine open a terminal window and type:
sudo gedit /etc/samba/smb.conf
Hunt through the file until you find the section called:
#======================= Global Settings =======================
A few lines under there (line 26 and 27 in my smb.conf file) you should see:
# Change this to the workgroup/NT-domain name your Samba server will part of
workgroup = WORKGROUP
You should change the "WORKGROUP" to whatever you call your home network - or whatever it's called on the Vista machine. Workgroup is fairly standard, but Microsoft used to have their home use products accessing a workgroup called "MSHOME" so if that is the "workgroup" that Vista thinks it is in, it might be worth changing it on the Ubuntu (and presumably the SuSE machine also.
If I can think of anything else at all, I'll let you know.