So I figured out what was breaking my autocomplete.
I have two blogs set up on mu using virtual sub-directories instead of subdomains.
The first blog is on the root using the default theme and acts as an outside blog (blog id=1) and the buddypress theme is on another blog for a private area (blog id=2). By doing this, I can have 1 wp-admin with a public and private area.
However, by changing the blog id in the bp-core file from 1 to 2 on line 20 for buddypress, it breaks the autocomplete ; but everything else works fine. i believe this is a bug …but if anyone has any suggestions on how to fix this please let me know.