“what the minimum system requires for the new version 1.6.1.2”
U3 can only be installed on SanDisk USB flash drives manufactured prior to December 09. All U3 compatible SanDisk USB flash drives will have the U3 Smart logo. If your product does not have the U3 logo it is NOT U3 compatible.
(http://kb.sandisk.com/app/answers/detail/a_id/240)
And if run on Windows 7 64-bit run it in Compatibility mode for Vista SP2.
