I found some issues related to links with multiple languages as below also with using html_meta_tags and with the Canonical URL link ticked.

for example for netherlands language would be the following:

sitemap has http://mysite.com/zenphoto/nl_NL/

in source code <link rel="alternate"... has href="http://mysite.com//nl_NL" (without slash- link doesn't work without forward slash)

and link from flag is http://mysite.com/zenphoto/nl

so there are 3 different links to same page of which one doesn't work without forward slash.

also in source code the canonical is http://mysite.com/zenphoto/nl but in site map is href="http://mysite.com/zenphoto/nl_NL

surely the canonical link should be the same as the link in the sitemap.

Ok, the canonical is probably a typo as well as the flag url. Both should be nl_NL naturally. I will take a look.

html_meta_tags should be fixed now. As for the dynamic locale plugin urls I will consult my colleague as I am not familiar with some of the recent changes.

All links should be using the shortened version of the language string. The sitemap links are updated in the 1.4.4 release stream to properly do this.

I will look at the other two and see what needs to be done. But this change (these changes) will not be retro-fit to the 1.4.3 release.