Hi prodigiworld, I can't see an obvious good reason for the errors you're getting on the page. I think your theme developer may be right, that there is no issue with the theme but in fact a plugin issue.
You say you've tried the plugin with twentyeleven, so we know that something is upsetting things when Prosense is activated, the main concern would usually be how jQuery is loaded by the theme but it DOES appear to be loading jQuery correctly and not doing anything silly in that respect. As such I'm not convinced that the issue is entirely the theme's fault (if at all). Currently I suspect a plugin conflict.
Have you tried disabling all plugins and then re-enabling one at a time? This is the usual next step. Leave the site on the Prosense theme, disable all plugins and then turn them back on one at a time. Turn on Squelch Tabs & Accordions first to see if you still have the issue with just my plugin and your theme active. If there's no issue then we can safely say that there is no conflict between your theme and my plugin (which is what I would expect as your theme appears to be loading jQuery correctly).
If you're using Chrome then I'd say keep the developer tools' console open so that you can see when there is an error: Enable one plugin, refresh the page, check for errors. When you get an error you will know that plugin is causing issues. We'll call this Plugin X.
Now as it's probable that TWO plugins are clashing, not just Plugin X is causing an issue on its own, it is advisable to go back through all the activated plugins and disable them one at a time (leaving Plugin X enabled) to see if the errors then disappear. When deactivating a second plugin fixes the errors we then know that (we'll call it Plugin Y) is clashing with Plugin X.
If you can do that for me and let me know what you find then that would help greatly. It's quite possible that Squelch TAAS is one of the plugins conflicting on your site, the question is what it's conflicting with and why.