OK, we have done some investigation on this. Although we were not able to locate the problem yet, we can walk you through pinpointing it. Please try this build: http://sysprogs.com/files/tmp/VisualGDB-5.4.4.2403.msi
First of all, please check that adding the header files to Solution Explorer adds their directories as COMPONENT_SRCDIRS to component.mk (although there are no source files in those directories, VisualGDB will use the COMPONENT_SRCDIRS statement to locate the headers).
If yes, please open View->Other Windows->VisualGDB Diagnostics Console and reopen the project. Check for diagnostic lines like “Will search for headers for <…> in <…>” and “Found <…> header files for <…>”. Do those lines make sense (i.e. do some paths look incorrect)?
If you are not sure, please let us know the full paths of the header directories, attach your component.mk and the entire diagnostic log.