Hi, 

Seems like the org-babel-parse-src-block-match function does something
wrong when parsing the block parameters. In my case I am trying to use the :file param with plantuml but it does not get down to the execute function.
To me it seems like the (string-match "-i\\>" switches) call messes up the (match-string
4) call further down.

Attaching a patch
Best regards,
Karl Berg