I'm affraid you misunderstood my ticket or I should say my explanations were not clear.
Since I use your excellent product, I have done more than hundred of restaurations. I know about what I speak!
Of course, I don't want to migrate my site with akeeba backup. It would be a nonsense !!
I just explained the context of my problem. Let me explain it the other way:
I need to know why path A and B does not give the same result
path A
host folder empty, database cleared
fresh install of joomla 2.5.28
fresh install of akeeba backup 4.1.0
fresh install of akeeba admin tools 3.4.2
--> working joomla 2.5.28 website
Backup of this working website as backup.jpa
test of migration using joomla upgrade: --> new website in joomla 3.3 works ok
path B
host folder empty, database cleared
restauration of backup.jpa using kickstart
--> working joomla 2.5.28 website (in my opinion should be the same as working joomla 2.5.28 website of path A)
test of migration using joomla upgrade: --> new website in joomla 3.3 not working (server 500 error as described in previous post)
I just can't understand in what the restaured joomla 2.5.28 website is different from the joomla 2.5.28 at the time of the backup.
In my head, this is the essence of akeeba backup. Both should be the same.
So if a website is the same after restauration, than at the time before the backup, it should work the same manner in both situations, which is obviously not the case here.
Please understand that I don't speak about upgrading through akeeba backup/kickstart. I just speak about saving and restoring the same version of joomla.
Can you please reconsider my question in this new point of view? I think I miss something but I need you help to find out what.
best regards
Jacques