FireWire target disk mode doesn't mount on desktop

Hi power users!

I have a Power Mac G5 using Tiger and an iBook G4 using Tiger. I have treid to use FireWire target disk mode on the iBook. Have done this many times before on other computers. have changed cbles, ports, and all but still the disk doesn't mount. it does go into Firewire mode thoug. On checking the system profiler on the G5, I found it recognized that there was a FireWire target disk mode computer connected!!! So what is the problem, ** do I get it to show up??

confusing..

cheers
Bert, using Macs since 1987

Do you know if your iBook is a post Sept 2000 model?

how does one tell?
it says in sys profiler:
machine model powerboook 6.5
CPU speed: 1,07 ghzbus speed: 133 mhz
boot rom version: 4,8 5f0
serial number
UV4280HRR72

I bought this used...

cheers
BERT

JUST FOUND out it was made 2004

is this relevant?

BERT

Serial number: UV4280HRR72
Name: iBook G4 (Early 2004)
Model: Mxxxx iBook G4 1.0GHz
Bus speed: 133MHz
Screen size: 14 inch
Factory: UV (Taiwan)