Listbox refreshing after click on combobox

See more:

VB

I have visual studio 2010.

I you have a listbox and a combobox, if you select a item from the listbox and after you click the combobox, the listbox refresh. It's like clearing the combobox and adding the items again.

I use visual basic 2010.
I'm not talking about the code. If you open a new project, add a listbox, add some items to the listbox, add a combobox, run the project, select one item from the listbox, click the combobox and the listbox for some reason refreshes.

Type of project. Vb > Windows Form Apllication.


Anyone knows why it happens???????