Error messages on mobile

I’ve been using WP Mobile Detector Mobile Plugin to automatically generate a mobile version of my WordPress site and it has just come to my attention that the site generates an error message when you go there on a mobile phone. I’m using WordPress 3.4.2 and I have to use plugins to customize the site since our IT dept. seems reluctant to give me FTP access. That’s also why I haven’t upgraded beyond version 3.4.2.

Anyway, here is the error message:
Fatal error: Call Call to undefined function twentyeleven_get_theme_options()in/hermes/bosaraweb053/b1876/nf.rockingr/thecatchconservation.com-redirect/wp-content/plugins/menubar-color-changer/menubar-color-changer.php on line 25

My first thought was to check my Dashboard and update the Mobile Detector Plugin. That created another error message at the top of my Dashboard. Here it is:
Please set the permissions on this folder (/hermes/boscraweb053/b1876/nf.rockingr/thecatchconservation.com-redirect/wp-content/plugins/wp-mobile-detector/cache/) to be 777 to allow the WP Mobile Detector to work properly. Ececute the following command via SSH: chmod777/hermes/boscrawebo53/b1876/nf.rockingr/thecatchconservation.com-redirect/wp-content/plugins/wp-mobile-detector/cache/

Menubar Color Changer is another plugin that I need to customize the site the way they want it. Does the first error message mean Menubar Color Changer is conflicting with the Mobile Detector Plugin?

Also, I showed the Dashboard error message to someone from IT, and she was concerned it might be some kind of hack, because she said the “777” part is granting read/write permissions. But maybe that’s legitimate because a Mobile Detector would probably need permissions to switch the format to a mobile friendly version.
Do you think it’s a hack, or do you think it’s safe to follow its instructions?

When I searched the forum for similar problems, I saw other users having problems with other mobile plugins. One discussion had several users recommending that a different mobile plugin be used instead.

Are their better mobile plugins I should be using instead?