Networking my Vista Desktop to XP computers

I have a home network set up using workgroups, with two printers attached to
my desktop running Beta 2 version of Vista. I just upgraded Vista to RC1 and
now none of my XP machines on the workgroup can access the printers on the
Vista RC1 machine. When I re-establish the workgroups, I get an error on the
XP machines that the workgroups are not accessable and that I need to contact
the Server Admin for the right priviledges. I have made sure that the
network on the Vista RC1 machine is the same workgroup, I made it
private....what am I doing wrong?

From the Vista Machine I can see my XP machines in the Network window, but
when I click on them, I get a message that I cannot access the machines?

I have been working on this for 5 hours...

Any help would be great!