Change the MouseHoverTime and MenuShowDelay to a non-zero value.
A. Check if the mouse hover time (in Windows) is set to 0? This is usually done with a tool like TweakUI or some other tool that lets the user change Windows settings.
Steps to check hover timer, follow the below given steps:
1. Go to http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx
2. Under download section on the extreme right side download TweakUI.exe.
3. Install this software by running the exe file.
4. Open this software from the "Start" , under Mouse, change the hover time to a non zero value eg. 1000mS. Check the attached screen shot(mouse hover time.jpg).
B. Also, make sure the MenuShowDelay is greater than zero. To change it, follow the below given steps