Ok, I have solved the problem by 'Locking' the function 'RunPopupMenu'. It seems a video memory problem or video driver, because I have test in other PC's and no problem appears. It happens when using multithreading and executing the RunPopupMenu. First I meke a RunPopupMenu at the beggining of the program and breaks. Then I 'Locked' the function and works but I have a Menu in the main panel. I need to click anywhere for the menu to disappear and relase the Lock for the program to start. Then I create other thread to meke the menu disappear and works. For last, I tried to hide the menu at the main panel by taking it to coordinetes 32000,32000 and it hangs again, the menu mist be vissible. A popup menu must be displayed and vissible in a locked function to have the opti
on to run the 'RunPopupMenu' in a multithreaded application running in Windows 2000.