What's wrong with this loop?

[hipopony66]

If MsgBox("Are you shure you want to clear the list?", vbYesNo, "Clear List?") = vbYes Then
    For x = 0 To cboMovies.ListCount
        cboMovies.RemoveItem (x)
    Next
Else
Exit Sub
End If

[MartinLiss]

For x = 0 To cboMovies.ListCount - 1

[MartinLiss]

BTW, you don't need to go through the items one by one, you can just do

cboMovies.Clear

[crptcblade]

Plus, you should probably loop through backwards to avoid an Index Out of Bounds error.

[Kunchesm]

If MsgBox("Are you shure you want to clear the list?", vbYesNo, "Clear List?") = vbYes Then
For x = cbomovies.ListCount - 1 To 0 Step -1
cbomovies.RemoveItem (x)
Next
Else
Exit Sub
End If

[Hack]

Also, no parentheses around the "x"

cbomovies.RemoveItem x

[techgnome]

Here's what's going on......

If MsgBox("Are you shure you want to clear the list?", vbYesNo, "Clear List?") = vbYes Then
    For x = 0 To cboMovies.ListCount
        cboMovies.RemoveItem (x)
    Next
Else
Exit Sub
End If

The first time through, x= 0, so it removes the first item in the list. Everything shifts down one position.
Second time through, x= 1, it deletes the second item, which use to be the third item, it's fine, until about halfway through, when X > number of items left.
Instead try, always removing just the first item. Like this.

If MsgBox("Are you shure you want to clear the list?", vbYesNo, "Clear List?") = vbYes Then
    For x = 0 To cboMovies.ListCount
        cboMovies.RemoveItem 0
    Next
Else
Exit Sub
End If

If speed is importaint, use Martin's solution: .Clear

[MartinLiss]

And you sure want to make sure that sure is spelled correctly