Sharing Vista folder in XP: 'access denied' for a folder I create

I have XP Pro SP2, and Vista Ult 64.

In Vista, I have made it a private nw, turned off password protected
sharing, turned on network discovery, file sharing and public folder
sharing. I have created a folder in C: called 'temp'.

In XP, when I 'map network drive', I see both the Vista 'public' folder
and the 'temp' folder. I can add both, but can only access the public
folder from within XP. If I try to access the temp folder, I get an
"access denied" error. If I r-click on the temp folder from within
Vista, I go to sharing, I click share, and I get "this folder is already
shared" I click advanced sharing, and the checkbox is checked for "share
this folder" - permissions in that box are set to full control change
and read (all checked). Under security, I gave everyone full control;
all of the 'allow' checkboxes are checked.

What should I try next?

As a first step get rid of this one and make another folder with a unique
name, temp is not a good name since many applications might create a temp
folder and many cleaning applications clean folders when the name temp. In
short it is a name used many times as part of the core system in computing.
After creating a new Folder set it Sharing as per this instructions.
As well as specific adjustment of each computer according to what it is
allowed to be shared.
Vista File and Printer Sharing-
http://technet.microsoft.com/en-us/l.../bb727037.aspx
Windows XP File Sharing -
http://support.microsoft.com/default...b;en-us;304040
Printer Sharing XP -
http://www.microsoft.com/windowsxp/u...utt_july2.mspx
Windows Native Firewall setting for Sharing XP -
http://support.microsoft.com/kb/875357
Windows XP patch for Sharing with Vista -
http://support.microsoft.com/kb/922120

I read the first link,

Vista File and Printer Sharing-
'_http://technet.microsoft.com/en-us/l.../bb727037.aspx_'
(http://technet.microsoft.com/en-us/l.../bb727037.aspx)

But a) have already done everything there, and b) that appears to be
Vista sharing.

I don't think that Network Map patch is going ot do anything.

Basically, my XP machine can access some Vista folders, but not all of
them. There is something about those folders that is different than the
ones I can share, even tho all of the sharing prefs and permissions are
the same.

G'Day. I had a similar problem a while back. Turned out to be a corrupt
file in the folder I was trying to access from another PC. I fixed it
by:
Making a COPY of the offending folder, then deleting files one by one
in the original folder until suddenly the remote PC could 'see' the
folder.

May be a useless response now, but maybe not...