I am attaching a patch file against the *.tar distribution that includes the following:
* Fixes makefile.win to successfully compile gtkrxdlg.dll on Windows.
* Adds a *.def file which is needed on Windows to export the functions. Otherwise rxapi can not load the functions. (There are other ways of doing it, but this is the simplest and least prone to error.)
* Adds the option to the make file to build a debug version of the DLL.
* Fixes a number of places in the C code where uninitialized pointers were being passed into the GTK libraries causing memory exceptions.
* Fixes a spot in the *.cls file where ~new was left off. (Unfortunately there were also a few places in the *.cls file that had trailing white space. My editor strips that out. So there are few more differences in the file than technically needed. But, hey, it cleans up the file a little. <grin>)
* Adds a windows-building.txt file that documents pretty well how to build the DLL on Windows.
With the changes you can build either a release or debug DLL on Windows that works. All the testXX.rex files run without errors. I didn't do any additional testing, but running your test programs gives a good demonstration.