Oh, no, please don't ever use the Reset tab on a jail broken iPad. When an iPad is jail broken, some of its system files get moved around and the Reset function(s) will not work. Guaranteed, you will bork up your iPad and have to start all over with a fresh install [anyway].
Your best bet is to download the 6.1.2 iOS (if you don't already have it) and use DFU mode to install it "fresh." Then, you can start all over again with a new jail break. Do note that if you don't put your backup on - you'll REALLY be starting from scratch; it'll be like new. Of course, you'll have to manually put everything back on and reset your Settings. But, sometimes, the effort helps in "cleaning" up.
Marilyn
Does this apply to both jailbroken iPads and iPhones? Is it also what one's supposed to do before selling or giving away the device (i.e. will the DFU mode actually also "wipe" the storage space (as per DoD 5220.22-M perhaps?), or can previous incarnation's user files be restored somehow?)?