I posted differents messages on this thread for one month now, SU developer team could see before to have some informations about my configuration.
Lot of message explain it is a problem with graphic card's driver.
For my part, even if the graphic card's driver have common points with our problem, my computer works fine some times, and works slow another time. this depends of boot sequence. If SU works Fine one time in a sequence of my computer, It works fine all the time before I Reboot
And If SU works slow, It work slow each time before I Reboot.
The call stack, I posted on this thread Before, is the same each time the slow action is occurs. and a call of WaitForSingleObjectEx Windows API return each time a Timeout result. (I change the duration of this time out period and If I put 10000 ms I wait 10000 ms. with a stop point in Debugger of Visual Studio and change processor register ...)
I can not find another information to help ... I don't know if my post is read by SU Developper Team ...
my conclusion now : Something during selection process need to lock sommething else to communicate beetween threads, main Thread UI and another thread ... and this lock is probably a dead lock ... and the time out in WaitForSingleObject is occurs each time ... (4264 ms or something like this, I have not the exact duration now ... Because my computer decided to worked fine today ) an it is why we need wait 4/5/6 secondes between each selection ...
Why ???? I don't know ... and my only one work arround to solve this problem is to reboot one time, two time, more to reach a good sequence for SU works fine
@yogesh : did you reproduce my scenario ?!