This is not a question, but rather a post so that the next person working with the Diamond Systems Universal Driver can search for and find this solution:
In order to get the DSCUD to work properly with the LabWindows/CVI RTE, the dscud.h file must be modified, as follows:
// -------------------------------------------------------------
// The following change is required in order to properly align
// the structures for use in the LabWindows/CVI RTE environment
// -------------------------------------------------------------
/* MS Visual C++ > 1.52 only - 1-byte structure alignment */
//#ifndef MSVC_1_52
//#ifdef _MSC_VER
#pragma pack(push, dscud_packing)
#pragma pack(1)
//#endif
//#endif
// -------------------------------------------------------------
In other words, the #pragma alignments must be made, even though this is not the MS Visual environment.