Connection Failure Between 2 Macs

While both volumes appear in each Mac's Finder, I get connection failures each way. "The Finder cannot complete the operation because some data in "afp://10.0.1.4" could not be read or written. (Error code -36).

I took the laptop into a Mac dealer and was able to establish a connection.

The computers are a powerbook G4 and an iMac dual core 2, both with OS 10.5.6. The iMac is connected via ethernet and the pb by AE.

With the test at the dealer was it the same deal - one on ethernet and one on wireless?