You do not need to install the 32-bit support package.

You can also continue to use Adobe OnLocation and Adobe Encore. Important: If you are upgrading from CS4 Production Premium or CS4 Master Collection you can continue to use your existing installations of Adobe Premiere Pro CS4 and After Effects CS4. After you upgrade to a compatible 64-bit operating system, you can install and use Adobe Premiere Pro CS5 and After Effects CS5. Until you upgrade to a compatible 64-bit operating system, you can install and use the 32-bit support package included with your purchase. The package contains 32-bit versions of Adobe Premiere Pro CS4 and After Effects CS4. To ease the transition to a 64-bit operating system, CS5 Production Premium and CS5 Master Collection include a 32-bit support package. If you are using a 32-bit Windows operating system, Adobe recommends that you upgrade to either: