3.2.2 is a rollup of all the patches issued since 3.2.1 was released. (The release notes listing the patches can also be downloaded from the website.) Customers using those patches should feel free to upgrade to 3.2.2, which is compatible with the previous 3.2 release, and can be used by any user with a valid 3.2 license.
To install 3.2.2, download the installer from the website. (Note that it’s named JNBSetup3_2.msi, just like previous 3.2 installers.) If there’s a copy of an earlier version of 3.2 on the machine, uninstall it (and remove the JNBridgePro components from the GAC), then install the new 3.2.2. Note that the 3.2.2 components can just be dropped into any application using an earlier version of 3.2; nothing needs to be recompiled, and the proxies do not have to be re-generated.