I'm truly sorry but left my experimental "Minimize to tray" code for Windows in the current MofoWallet release.
This will cause mofowallet to "disappear" when you minimize it. It's not actually gone, just hidden but the icon in your tray will not display since i did not yet find a nice icon to use for that.
If you do minimize mofowallet and mouse over your tray, you will find that there is a (invisible) icon which you can click to bring back mofowallet.
I'll get an update tomorrow
Downloads are updated, fix is applied.