OnEvents are processed from right to left, so show_window=(MainHUD.Inventory) is initializing the show_window value but not displaying it. Also, show_window=(MainHUD.Clock) is unnecessary for the clock window; OnHide="visible=true" is all the clock window needs to display. The code you'll want to use is:
Code:
OnHide="visible=true show_window=(MainHUD.Inventory) show_window=(MainHUD.Inventory)"
Quib