Well...with TraySetToolTip we have only two choice:
1) Use a custom text
2) Use the default autoit string
With internal autoit function there isn't a way to not set a tray tip when mouse hovering the icon. The main problem is i prefer and want to use the default autoit icon without create a "new" one or the things will complicated, like we can't use TrayGetMsg(), TraySetState() etc. or other internal Tray Function.
I have think to use:
a ) _WinAPI_ShellNotifyIcon using $NIM_MODIFY on the autoit icon for pass an empty string to the tip. Creating a new one like here:
http://www.autoitscript.com/forum/topic/156233-add-more-icons-in-the-notification-area/#entry1129773
Isn't a problem but i can't find a way to edit the original one 
b ) Intercept some message like WM_TRAYNOTIFY and return 1 to the tray tip, or something like that but this is only an idea 
Have a nice day and thanks for the help
