We finally decided to create a mobile page for our site
Our website is an old version (5.0) of drupal and we don't want to upgrade the theme (we did this before with another site and all rankings were gone for more than a year).
So we created a page on a subdomain (mobile.oursite.com) and this page is presented to users who come form a mobile browser.
So basically, mobile users click on the link in search but instead of landing on website's page, they are redirected to a mobile subdomain.
Can this create a problem with Google?