I just found that if I try to use the remove from cart button on the minicart that I get error below. It works fine from pc where it brings up dialog box to click ok but on mobile it goes to error screen and makes report. I'm using one page checkout but not sure that has anything to do with it.
a:5:{i:0;s:16:"Invalid form key";i:1;s:935:"#0 /xxxxxx/xxxx/xxxxxxx/xxxxxxxx/app/code/core/Mage/Checkout
/controllers/CartController.php(604): Mage::throwException('Invalid form ke...')
#1 /xxxxxx/xxxx/xxxxxxx/xxxxxxxx//app/code/core/Mage/Core/Controller/Varien/Action.php(418):
Mage_Checkout_CartController->ajaxDeleteAction()
#7 {main}";s:3:"url";s:97:"/checkout/cart/ajaxDelete/id/10792/uenc/aHR0cHM6Ly93d3cubG90bmxsYy5jb20vb25lc
3RlcGNoZWNrb3V0Lw,,/";s:11:"script_name";s:10:"/index.php";s:4:"skin";s:7:"default";}
