Although we haven't experienced that issue exactly, we do know that Audiobar doesn't always play nice with iOS - and we're trying our hardest to remedy that. A few question to help us out: which iOS version are you using? Do they not scroll up/down, or also left/right? Are there any other plugins you use that may be inhibiting audiobar? Finally, is this a mobile version of the site or the full site?
A link to the site would be helpful, if possible.
Carlo (the programmer for the plugin) has full mobile support pretty high on his to-do list. That being said, I'm not sure when we could assure you full mobile support. Thanks for your support!