I posted a fix. You can view the patch at: http://pkp.sfu.ca/bugzilla/show_bug.cgi?id=3432
The limitations of the plugin have to do with the way in which pages are loaded based on the Header of each page. This means that when you want to load the first page, say its titled "Home" you have to use the url .../cms/view/home. If you translate this page to spanish, then the URL changes to .../cms/view/inicio.
This means that someone viewing cms/view/home who changes the language to spanish, will remain on the english language page and not switch to the spanish one.
I have made a note to refactor the CMS plugin, because there are a few things that don't work quite as I'd like them to. See bugzilla entry http://pkp.sfu.ca/bugzilla/show_bug.cgi?id=3431
For people who don't care about having the table of contents in the sidebar, I am thinking that another CMS plugin should be developed which forgets all the crazy parsing things and just provides simple static pages. If I can find some time, I will try to develop something for this soon.
Any feedback/comments welcome.