clEnqueueWriteBuffer() -4 error when using more than 2 rule files

When using  oclhashcat I get this "clEnqueueWriteBuffer() -4" error when I use more than two rule files in the same command.

With 2 rules everything is ok. With 3 rule files, I get this error.

The rule files only have short rules with maximum 4 arguments for each line?

Any idea or solution??

thank you

tibit