I have drupal 6 with mobile-tools module and idrupal theme for iphones. sometimes my website starts displaying mobile theme (idrupal) for desktop, and the only way to return back to normal theme for desktop is to flush all caches. is there a permanent solution to disallow idrupal theme from being used for desktop?
If you are using varnish in front of the your server, then it will completly cache you request, Mobile tools will not be able to determine the useragent is mobile or desktop to redirect the theme.
One of the solution is to determine at varnish level and redirect to a m.domain which always has a mobile theme attached to it.
Refer the following links