Sharing Files With Vista (build 5308)

I can't figure out this problem. What I've done is;

1. Copied a directory with lots of folders and files from an old Windows server to a new fresh Vista-installed computer.

2. Set up a proper account, and assigned ownership to the whole folder + all subdirectories

3. Shared the folder

The trouble is when I am trying to access the share from some of my other computers, I get a mixed result using the same logon-account;

PC 1: Can access some folders, others fail - showing the following message "FOLDERNAME...is not accessible. The specified server cannot perform the requested operation"

PC 2: Can access a few more folders than PC1, and there are files and folders missing (when comparing to the directory structure on the host machine). However, this computer does not come up with any error-messages - but rather shows empty directories.

I am pretty sure I have the permissions right. I have tried disabling all firewall software - but that didn't make a difference. I have also checked the local security policy on all three machines "Local policies > security options > Network access: Do not allow anonymous enumeration of SAM accounts and shares" is disabled on all three computers.

Both the clients are running Windows XP Professional with all updates.

I hope someone has a clue, I sure don't!