Thank you for your answer Robert. I am feeling less alone
I have tried to run this application on another server and it works so I think the probelm is not coming from the code itself.
I have tried the debugger with the limited reloading (10 lines are loading for each select or LOAD) and the reloading still stops at the same moment.
I've found out that if I put one line in comment, it works...
The line is a store :
STORE table into folder\table.qvd ;
I don't know what's wrong whit that line
EDIT: I've found the problem : the "table.qvd" was opened in another program ... so I renamed my qvd.