[X4U] Mac locks up when attempting use file sharing

[Kansas Territory]

I have a dual G4 tower running latest OSX.

When ever I attempt to send it a file via filesharing, the the system  
attempting to start the file transfer, locks up finder..
If I attempt to start the file transfer from the G4 in question..   
the G4 finder locks up..   I have waited and waited and waited, no  
file transfer ever happens.

I've tried sending files to this computer from two different iMacs.   
one an intel, other a G5.  and I've tried from a MacBook as well..   
same symptom persists.

I have discovered that these "OTHER" macs have no problem file  
sharing amongst themselves..  imac to imac, macbook to imac etc.. all  
work .

All running the latest OSX versions.. and very limited 3rd party  
software on any of these computers.. and otherwise all healthy, VERY  
stable computers.

I've tried running fix permissions etc. on this G4, but no change was  
affected.

One difference which occurs to me is that this G4 is the only  
computer plugged directly into the Vonage router.  the iMacs and  
Macbook were all connected to the vonage router via Wireless connection.

Anyone with any other suggestions I might try  ??

Kansast