For one of my sites, i use WP Super Cache along with WP Mobilizer to serve the mobile theme for mobile/smartphone visitors.
What is happening, from time to time, the desktop version shows the mobile site and mobile site shows the desktop version.
This is frustrating when a mobile visitor is unable to see a mobile optimized theme.
For the record, W3 Total Cache does not work on my box and i switched over to Super Cache after my dedicated server crashed on a default install of total cache. Even before it could be configured, load spiked so much that the server kept running out of memory.
back to the issue, i posted a support ticket on both the plugins @wordpress, but not a single response. I emailed the authors offering to pay them for their time but still nothing.
Any help on this would be greatly appreciated.
Does the site work after removing the Super Cache plugin? I guess the issue is when a visitor on same IP visits your website from different devices the previous version of the site is loaded. I suggest not to use WP Super Cache as it is outdated and many problems are reported after updating WP, you should move to some other cache plugin like http://wordpress.org/plugins/quick-cache/