Ok, this is solved (well at least now J2EE 1.3 RI is launched
This is what i was afraid of.
After going through web search and find a sun bug about j2ee 1.3 describing exactly my problem, declared as "closed, will not be fixed".
Their explanation was incompatibility problem between j2ee 1.3 and j2se 1.4.
So i tried to download sun java system application server (sjsap) only from j2ee 1.4.
I went through HFE tutorial (first chapter) with only a few deploytool differences, but managed to finish it. But, my client finished, i was unable to make the whole thing work together.
I decided to give up and to do what i didn't want to : remove jdk 1.5 and setup jdk 1.3...
I did, rebooted, and tried, and the j2ee 1.3 RI appserver launches correctly.
I go again through the tutorial in HFE to redo the whole EAR creation process, and i'll tell you if the whole thing works.
Wait and see ! (and hope...
)