Airborne Operations - Can Not Deploy

[Ranger70]

I have the free download of WinSPWW2 (with the patch version 6?). I use a Windows 7 machine.

When I try to deploy parachute units, I get an error message telling me transports are not available for the mission.

I have tried the "battle" setup with all of the missions. I buy parachute units, load them in purchased transports, and then try to deploy them before quitting the deployment phase. I can cycle through spotters, artillery and airborne, but the airborne option shows the message telling me I may not deploy transports due to the mission type.

This also happens in the stock campaign about parachute forces in the Pacific.

I would appreciate any advice.

Many thanks, John