TOAD disappear when minimized via View Client

Hi! I use Horizon View 6.2 successfully. But I have trouble with TOAD application. TOAD for Oracle starts and works successfully via View Client (3.5.2 and 4.0.1), but TOAD disappears when I click minimize button.

If I restart application, it start as new (i.e. connections and queries are lost). Other applications work fine with minimize button. I tried to use View Agent 6.2.0 and 7.0.0. I tried to run TOAD with Compatibility Mode.

Any idea?