Hi Simonel,
I didn't !.
It's still rather slow, but over time it's become better 10 to 20 secs. but I still have no idea why, and that really bothers me. I still think it's the creation of a SO in the backend that makes it so slow but why ?

Hi Walther,
I discovered a link with the Helpdesk module. In the Sell & Track Hours section I unchecked the "Time Reinvoicing" function and it returned to 1-2 seconds loading time.
When saving the line in the order, it performs a check procedure in the tasks, and if there are many here, it starts to delay the process. of course there can be other causes.

Hi Simonel
Well spottet :-). I haven't Installed installed the Helpdesk module, but your findings might be the path into getting to the root of this bugger. I'll dig into if there's any linking to calendars, time card or other peripheral things ...

I am waiting for good news! :))