This is a bit of a long shot but the plugin works well for me and seems like the support community are pretty knowledgeable, so here goes...
I have WPTouch working ok on http://www.isthismusic.com - apart from the problem that the menu and the search in the top bar don't work (the menu 'responds' to a touch but there's no dropdown).
I actually tried disabling all 30 of my plugins, and, you guessed it, the menu and search operate ok!
But I was hoping that someone here might have an idea of any conflicts before I start on what might be quite a task in locating the bad plugin (plus, they're all pretty essential for the site's operation).
I already tried the suggestion elsewhere or going onto Advance mode and "Use jQuery 2.0 in themes" but it didn't help.
Any ideas that'll save a lazy site admin (with not that much tech knowledge) wading through the plugin list?