Check out this thread: Managing the 5.5 Install
The plug-ins just have to be manually copied into the CS5.5 plugins folder, since (I'm assuming) old installers don't recognize the new CS5.5 folders.
As Colin says migrate the plugin from CS5 to CS5.5
BCC7 work perfectly in AE 5.5.
Boris and Natasha are still not alive. I forgot to mention that I am on a Mac.
I'm not sure exactly where these files are kept at a Mac, but the path should be pretty similar to this: \Adobe\Common\Plug-ins\CS5\MediaCore
If you just search for "mediacore" you should get both hits, for copying the originals and pasting to the CS5.5 folder.
ok, but with a new install of adobe products cs 5.5, where is continuum installed? nothing appears on after effects or premiere, to copy the borisfx folder into ...common/plug-ins/cs5.5/mediacore dont have good result too...