Problems creating outbound Tradacoms invoice documents v6.5.

Is anyone using the new Tradacoms functionality in the WmEDI package ?
After having just about got my head round creating files using the Tradacoms adapter in v 6.1, I am now really struggling with the new functionality in v6.5.2. Despite having read the manuals several times. Every time I attempt to run a service in the WmEDI.b2b.edi.tradacoms.compose or simply tradacoms.convertToString I get a java.lang.NullPointerException. Please can anyone out there offer any suggestions…