Problems on mixed network

I have a desktop computer with XP Home SP2 and a laptop with Vista Home
Premium.

At one time I had a wireless network setup that more or less worked.
However I had to do all file copying or sending from the Vista laptop ..
couldn't do anything with the XP desktop but view files on the laptop.

Anyway it worked enough to get by with.

I have a Canon Laser all in one printer and when I tried to install that it
said it was incompatible and I said to do it anyway and it worked just
fine.

Da Boss could use the laptop in the dining room and send stuff to the
printer in the computer room with no problem. And the printer is hooked to
the desktop via USB cable.

Then for some unknown reason the network went to pot and I can now no
longer print from the laptop and the laptop does not see the desktop when I
look at network places.

The desktop sees the laptop but it is actually showing me shared folders on
the laptop that no longer exist. The folders show up in network places but
if I click on them I get the error message that I don't have permissions
and the network isn't found etc. etc.

I've been tearing my hair out but can't seem to make any progress.

Both computers have the same workgroup name and file and printer sharing is
turned on on both machines.

I have no clue why the desktop is showing non existent folders on the
laptop. I've tried refreshing the view with no success. They are still
showing up.

All suggestions / solutions appreciated.