You can get the latest ndiswrapper from the official website on Sourceforge (at the time of writing version 1.57 is the latest stable release). Ubuntu 11.10 has ndiswrapper-common version 1.56, Ubuntu 12.04 offers version 1.57. Honestly, although having the latest release of any software is ideal, I highly doubt that using ndiswrapper 1.57 over 1.56 will really make a big difference with your wireless adapter. I recommend first trying with the ndiswrapper-common package available in the repositories, if that doesn't work, then grab the latest stable release from the Sourceforge website and install it from source. Alternatively, you may be able to download the deb packages (your 32-bit compiled binaries) in launchpad for Ubuntu 12.04, but this could break your system and is not encouraged.
Ndiswrapper is tricky enough as it is for those configuring their wireless adapter in Ubuntu for the first time, it's best not to complicate things and use the version available in the repositories if that version can suffice.