If you are using the use the interfaces in a different thread than the one creating the control, you need to marshal it to this thread (CoMarshalInterThreadInterfaceInStream and CoGetInterfaceAndReleaseStream, which probably were made to win the WIN 32 API lyrics award) chopping strings usually isn't a symptom of violating apartment boundaries, but MSHTML ctrl has a few message loop interacitons that make that possible.
Some of us walk the memory lane, others plummet into a rabbit hole
Tree in C# || Fold With Us! || sighist