ongoing discussion with Rick at mathworks over engOpen() calls failing. if no proper solution, consider setting a flag in loder calls to GET_INFO so that the engine starts in single use mode, so that we get info back. (starting in singleuse() mode avoids the NULL problem but is slower). or find out how to make it work properly in shared mode.
UPDATE: see http://brahms.pbwiki.com/MathWorks5CG893 (have to use engOpenSingleUse(), or engOpen() with pausing)
(not implemented yet, so open bug)