WiFi file sharing between Macs is incredibly slow - when it works

I've got a new 20" iMac Core 2 Duo 2.16GHz machine that I've setup to share files with my 12" PowerBook G4 1.5GHz. Both machines are wirelessly connected to a common WiFi router. In both machines I went to System Preferences -> Sharing and then enabled Personal File Sharing.

From the iMac, when I click on network I can see a link to the PowerBook and I can log in as myself (a Registered User). I can manipulate files without issue. Copying files form the PB to the iMac, however, is exceptionally slow. A 675MB file took >25 minutes to copy from one machine to the other. Shouldn't I be getting something much faster?

From the PowerBook Network window I can see a link to the iMac but when I click on it a window titles, "AFP Connection Status" pops up and in it it says, "Looking up blah, blah IP address. Eventually I get a "Connection failed: The server may not exist or is not operational..."

If anybody has any advice as to where I should start with the problems I'd greatly appreciate it!

As far as I'm aware it's never suggested to Stream Files Wirelessly Twice... that appears to be what you're doing. You would notice a marked improvement if you connected one to an Ethernet Port.

Also considering you're using the same Wireless Router, I assume this would degrade the power of the wireless signal.

Aha, bingo on #1! I connected the iMac to the router via an ethernet cable and a couple hundred MB streams in under 2 minutes - AWESOME. Thanks!

The other issue remains however.

One down, one to go. Thanks again.

Sorry I missed your second problem.... I had a slightly similar experience when connecting to a Windows PC.

It wouldn't find server (Windows PC) and would come up connection failed, I just assigned my Computers an Permanent IP Address on my Router and everything seems fine now.

I don't know if this could benefit your situation but it might be worth looking into the fact whether your Powerbook is looking for a Certain IP when in actual fact your MacBook is being assigned a different IP every time it connects to your Network.

So your Powerbook is looking for a Computer attached to an certain Ip that is no longer assigned.

Hope that Helps, might be worth a try.