Steven Zahm@ Karine
Is the jQuery compatibility option still enabled or not? If it is not, please enable it even if it has no effect that you can see. The purpose is so I can see if it is able to override the theme or not so I can eliminate the old jQuery version being the issue or not.
ps. You should probably ask the theme dev to release an up to fit jQuery regardless if it is determined if this is the cause of this issue or not for a couple reasons. Most importantly, the version included with the theme is 4yrs old. This will start causing you troubles with plugins expecting a current version included with WP. And second, related, it is considered bad practice to override the the jQuery version in WP because plugins are expecting the version included with WP which can cause compatibility issues.