I believe it is a bug in Magento. I've confirmed same on new magento installation 184.108.40.206 and on 220.127.116.11.
'Search' and 'Reset filter' buttons does not work on Shopping cart tab - backend (Manage customers). When checked using firebug, it displays an error - ReferenceError: id_38724ef8c3ffc5020408a02bbe80530eJsObject is not defined
Edit: Found nothing except this link: https://github.com/magento/bugathon_march_2013/issues/36 which provides no help!
If anyone has found a solution, please share