Difficulties transferring files between Lion and Leopard

Question

Hello all-
The short: Our two computers running Leopard can transfer files across our home network to all other computers with no problems, and can grab files from other computers with no problems. Our new iMac Lion can't do any of that.
The long: We have recently purchased a new iMac (Lion 10.7.3), and have connected our old 2006 iMac (Leopard 10.5.8) to the TV and stereo (and directly to our B/G/N Airport Extreme) for use primarily as a media server. We also have an MBP (Leopard 10.5.8). All three computers are shared on a home network, and I believe I have set up the sharing and permissions correctly.
From both Leopard computers I can transfer files back and forth, as well as access files on the other and bring them over. Additonally, from both Leopard computers I can do the same while accessing the iMac Lion- either transfer files to it, or connect to it and bring files over. This is what leads me to believe that the sharing is set up correctly.
However, when I am on the iMac Lion and try to do any of these processes with either of the Leopards, I get a confusing set of steps and ultimately, failure.
First, I when I try to transfer or copy a file I get a window asking:
Finder wants to make changes. type your password to allow this.
It automatically fills in the admin username for the iMac Lion. While it is waiting for me to enter the password, a progress bar pops up stating that it is "Preparing to copy to "(Location)", and then I enter the password.
As soon as I enter the password, a new window tells me that:
A newer item named “(filename here)” already exists in this location. Do you want to replace it with the older one you’re moving? (note- this 'file' has just been created, it is the 'newer item', and it contains zero kb of information).
and gives me three options: Keep both files, Stop, or Replace
If I choose Keep both files it immediately begins duplicating the empty version of the file and it will make thousands of duplicates in mere seconds. I must kill Finder in order to make it stop.
If I choose Stop the process simply quits.
If I choose Replace it says The operation can’t be completed because an item with the name “” already exists. (the quotation marks are exactly like that with no filename inbetween).
Summary: I am at a loss as to how to proceed. I cannot seem to find why the iMac Lion cannot do anything to the Leopards, while the Leopards seem to have full abilities, even with the Lion. I have tried turning off AFP and turning on SMB to no avail.
Any advice would be greatly appreciated. It is incredibly helpful to be able to share files between our systems, as the iMac Leopard has PPC programs that I cannot install or run on Lion, and so I keep them around in case I need them. Plus, my wife uses the MBP Leopard for specialized research and many of the programs they use do not run with Lion.
Message was edited by: Jeff Sorley

Answer 1

Repairing the permissions of a home folder in Lion is a complicated procedure. I don’t know of a simpler one that always works.
Launch the Terminal application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Terminal in the page that opens.
Drag or copy — do not type — the following line into the Terminal window, then press return:
chmod -R -N ~
The command will take a noticeable amount of time to run. When a new line ending in a dollar sign ($) appears below what you entered, it’s done. You may see a few error messages about an “invalid argument” while the command is running. You can ignore those. If you get an error message with the words “Permission denied,” enter this:
sudo !!
You'll be prompted for your login password, which won't be displayed when you type it. You may get a one-time warning not to screw up.
Next, boot from your recovery partition by holding down the key combination command-R at startup. Release the keys when you see a gray screen with a spinning dial.
When the recovery desktop appears, select Utilities ▹ Terminal from the menu bar.
In the Terminal window, enter “resetpassword” (without the quotes) and press return. A Reset Password window opens. You’re not going to reset the password.
Select your boot volume if not already selected.
Select your username from the menu labeled Select the user account if not already selected.
Under Reset Home Directory Permissions and ACLs, click the Reset button.
Select  ▹ Restart from the menu bar.