Problem with Combobox Events in Windows 7

Question

Hello, 

I have created one User Control which contains Combo and Listview such that When User Click on Combo's dropdown arrow it shows list view. For that i use Dropdown event of combo. when user click on other part except arrow, it hides listview if listview is open.  it works fine on XP and Vista .. but cannot work on Windows 7.

In Windows 7 when the drop down event called , it also calls click event..So list view never seen. while it is not happening in XP and Vista. 

then i try to change the Event instead of using click to hide listview, i use Dropdown close of combo.. it solves the problem on Windows 7. but creates same problem in XP and Vista.