just wanted to let you know that the problem is now resolved..
sorry for the unreadable code :p
anyway, the code wasn't the problem.
I tried to run some of the pushURL samples provided by rim and the first ones (below 4.1) wouldn't work at all for me but 4.1 was fine.
I didn't try the versions above 4.1 but I suppose they work fine?
So if anyone have the same issue, first try to run the samples.
Also, this was only one part of the problem.
It seems that while trying to debug the app, some ports remained open or pending or whatever...
By mistake? I reinstalled the OS of the black berry and everything worked fine, without even modifying the code.
Also, we use a lotus domino server and the handheld was still linked to a former employee so we had to assign the handheld to my account...
But now it works just fine