http://bugs.winehq.org/show_bug.cgi?id=15642
--- Comment #24 from Michael Monreal infernux@web.de 2009-02-18 16:39:19 --- (In reply to comment #23)
Either right-click and run with program installer or with msiexec. Both work for me. Note that I am using 1.1.14 and 1.1.15.
I can second that, installing the plugin worked for me in 1.1.14 (with a clean .wine/ directory)