Shared folders, different results.

OK, I'm not sure what settings I need to tweak, but I'm sure someone here as experienced this and might know.
I have a desktop and a laptop, both running XP (desktop XP Home SP2, laptop XP Media Center SP2). Both systems are running ZoneAlarm firewall and both are current and set up properly for my network and for file sharing. I have file sharing/print sharing set up, and have no problems sharing files both ways...except...
On both systems, I have "My Documents" shared, with both boxes check to "Share this folder on the network" and "Allow network users to change my files".
So if from my desktop I open the "My Videos" (for example) subfolder that's located on the laptop, I have full access to the files; i can copy/move/save/delete whatever i want. I can copy files from the laptop to the desktop with no problem. But then on another folder that is also a subfolder of "My Documents" I can view the contents, but I can not save/copy/move/delete these files. When I try to copy a file from the laptop (when I am using the desktop) I get an error message that says "Can not copy (FILENAME): Access is denied. Make sure disk is not full or write protected and that the file is not in use".
So WHY would I get this message, when:
1. other subfolders under the remote "My Documents" share BOTH ways no problem?
and
2. I am trying to copy files to the computer I am using?

I'd understand if I had some setting wrong and was trying to copy TO the remote PC, but not when trying to copy FROM the remote PC when I can see the files and they are shared. So in this instance, if there's a file I want that located on the laptop, I have to use the laptop to copy to the desktop. I can't access it from the desktop. Make any sense?
Thanks for any help!

 

Anyone?

 

What are the security settings on the folder you can't copy from? Everyone with full control?

Look a event viewer and the security log. Any events logged when you try to copy a file? What event id/code?