I figured out how to fix the bug i reported awhile ago. The problem was that when making the keyword field for entries without keywords defined in the `:PROPERTIES:' drawer,  org-bibtex uses `bibtex-make-field' from `bibtex.el'. This function sends up an error if there are no fields defined for the type of bib entry you are calling it on. In order to make it work on non-standard bib types you would have to define the fields associated with these types in `bibtex-entry-alist'. 

One way to deal with this would be to mention this in the appropriate docstrings. However this would leave org-bibtex somewhat unstable and dependent on variables outside of `org'.  I think a better solution is to make the keyword field without calling `bibtex-make-field'. This can be done with a couple simple regexp functions.

Here is the patch that I came up with. Let me know what you think.

All best,

Leonard