When presented with a collection of input files, some of which are OCaml source, the output of ctags depends on the order of the input files. For example:
$ find . -name \'*.ml\' | ctags -x --filter=yes | wc -l
$ find . -name \'*.ml\' |sort| ctags -x --filter=yes | wc -l
This happens whether or not the \'filter\' feature is enabled. I have only observed it when some files are OCaml source. Observed with Ctags version 5.8 on Mac OS 10.6.3. Offending source attached.
Source files illustrating possible bug above