Scary Handling Problem

First the equipment:
2009 Winnebago 29T class C on 2008 Ford E450 with V10 Triton
2007 Jeep Liberty with 4 wheel drive
Blue Ox Tow Bar and Tow Plate
Brake Buddy

Now the problem:
When driving the Winnebago or Jeep separately, they do fine. When you hook them together, it becomes a white knuckle experience. When the toad is hooked up, driving at city speeds, the steering on the RV seems stiff and doesn’t try to return to center after a turn. With the toad hooked up, driving at highway speeds, when I try to correct for a wind gust or a truck passing, the RV seems sluggish in responding then overcorrects and must be corrected back. This leads to overcorrection to the left followed by overcorrection to the right and this continues for several cycles. Then it’s back to a constant wandering between the lines. The tow bar handles are both in the locked position and there is no slippage in the bar. The alignment on the Jeep checked out OK. Also had the shocks on the RV checked – they’re OK. No oversized tires on the vehicles. Sure would like to find an INEXPENSIVE solution to this problem. Any suggestions?