Connecting Powerbook to Imac


I have a similar problem to a question asked on April 1 2005. My G3 Lombard and my G4 iMac are both running OSX 10.3.9 they are connected to a Belkin wireless router(the iMac has a cat5 and the powerbook is wireless)Both machines run sweetly and connect to the internet. IP's are via DHCP and appletalk and sharing are enabled.
The iMac will connect to the powerbook within a few seconds, mount volumes etc.The powerbook can see the iMac but just times out when i try to connect the other way. Although i can use the iMac for taking and leaving files on the Powerbook it is anoying not being able to share the other way round especially where iTunes is concerned.( Lombards being only slightly more expensive than airtunes)
Please help :)



ps. Technical detail for reply no problem,Macs for last 15 months but previous Wintel/Novell admin/tech experience.....for my sins!