Hi(Bonjour!
Do you see your camcorder in System info application in utility folder?
Can you use it into iMovie ?
You have to plug your cam, power it, lauch FCE, set the correct setup in easy setup before capturing.
Give us more details about your computer configurations, Mac OS and quicktime version ?
On what port do you plug your camcorder ? IS there any other device daisychained with it on firewire ?
Is you camcorder is set correctly to output via Firewire port?
See this link about firewire connection:
http://docs.info.apple.com/article.html?artnum=301852
Michel Boissonneault