File sharing and music sharing in iTunes not working on local network

Question

Hi Folks
I am now going to make a topic of my own this time. Here is how it doesn´t work:
I have a MBP with Mac OS 10.5.4 connected via Airport to my local network. The switch is a zyXel 2602HW-D1A. On my network there is an iMac Flat Panel 800 mHz and an even older iMac bondiblue rev. A. Both of the old ones are running (smoothly) on Panther. The two old ones are connected via ethernetports (wired) on the zyXel-switch. I also have an Apple TV connected wireless to the switch. There is also two printers connected to the network.
Until recently, don´t know exactly when, everything has worked just fine. The two old macs showing up perfectly in the sidebar of a Finder window. I could also connect to them via the command K. Musicsharing in iTunes also worked very well. But now it is impossible for my MBP to connect to the other Macs. They show up rarely in the sidepane af the Finder window, but when i try to make a connection it is impossible. It just turns the little wheel for a short while and then it says connecting failed. Also the command K command doesn´t work. The other way round is no problem. The two old ones connect perfectly together and to the MBP. Musicsharing is also lost FROM the MBP. There is absolutely no problems in the connection to the Apple TV from the MBP as well. All three Macs connect perfectly to the internet. I can also print from the MBP. AND it strangely connects perfectly to all PCs on my job-network, it is a PC only, LAN.
So far i have tried almost any combination of turning on and off firewall, allow only special sharing etc. For now the firewall is set allow everything to connect (and it has always been that way) Network settings has also been toggled in any way they can. I have done all three cron jobs and repaired permissions a few times. The zyXel switch has also been reset and restarted.
I also have a strange minor problem: I can´t open log via the show log button in the advanced pane of firewall settings. There just nothing happening when i click the button. I also had another problem in turning on Airport the other day. I toggled on and off a few settings (Appletalk on and off did the trick) and then it suddenly worked.
I have a strange feeling of something corrupt on my MBP. Or is it just that networking on Leopard is a bit unstable??
I would appreciate some help her. I am sure that the problem lies within the MBP, or what do you think?
Cincerely
Mads

Answer 1

Thanks - the weekend was very pleasant indeed!
I agree that something seems to awry in the Leopard MBP. The question is "what". The symptoms now are:
1) iTunes music sharing from MBP is broken
2) Connecting to Panther Mac via AFP is broken (although one Mac can be connected via IP address)
3) Machine works well on a Windows network
Based on all of this, I would guess that there is a problem in the "Bonjour" networking of the MBP. You could try:
1. Using a different account to see if it is local to your user id.
2. Failing that, removing your com.apple.AppleFileServer.plist and com.apple.AppleShareClient.plist files from /Library/Preferences
Outside of that, I would have to do some more digging.