See Screenshot.
Squirrel is reached via https://expresscoach.servers.eqx.misp.co.uk:2096
Sometimes, the sidebar disappears. The only workaround is to close the Tab, Quit Safari and relaunch.
iPad 3, iOS 6.1.3
This has not so far happened to me on either Windows or Mac desktop or laptop machines.
After relaunch, the sidebar reappears.
You may want to contact your provider or cPanel. I don't think anyone on the SquirrelMail team has an iPad to test with, so we'd rely on you or your provider to diagnose the problem.
Thanks