Hi,
I've noticed on Google Webmaster Tools a lot of pages with URLs like www.mysite.com/mypage.html?device=desktop
It looks lite those URLs might have been created by Mobile Joomla because otherwise Joomla 1.5 that I use does not track the visitor platform. Is it really so or do those URLs originate from somewhere else?

Google does not index those pages because they all are duplicates of the actual pages (without ?device=desktop in the URL). But probably it might have a negative impact on the site's rankings because Google thinks that there are a lot of duplicate pages on it.

Hmm. Mobile Joomla adds both correct canonical and and robots=noindex,nofollow tags on pages with forced device mode, but it looks like we missed device=desktop mode (for safety reason Mobile Joomla tries to don't affect desktop mode at all). I'll try to fix it in next release.

Thank you. A strange thing is that, when I temporarily disabled Mobile Joomla, those URLs were still operational. That's why I was not sure about their origin. But you know better of course. If it's really Mobile Joomla, would be great if you can fix this.

Those links are generated by Mobile Switcher module, but they have rel="nofollow" attribute and shouldn't be indexed by search engines. I don't know how they come into search index, but hope that canonical url and robots=noindex,nofollow tags on that pages will fix the issue.