Carrying on the topic of IFilters from the previous post, Adobe does not currently have a 64-bit PDF IFilter.  My recommendation is to use Foxit Software's PDF IFilter.  With SharePoint, if you are running a 64-bit server farm, the other option is to separate the index component functionality to a 32-bit server and load the 32-bit Adobe PDF IFilter.  (Although, I don't believe this to be a real solution in a true 64-bit SharePoint server farm.)

In examining and utilizing Foxit's PDF Filter, I tried their PDF Reader.  What a refreshing experience.  If you are tired of Adobe Reader taking ages to open and load, Foxit's Reader will please you.  It's all the functionality you need in a reader trimmed down with no bloat.  It also comes in x86 and x64 versions.

Give it a try...