I have everything setup right out of the box pretty much...
-Firewall ports for SQL open
-Local arcgis account on both ArcGIS Server box and ArcSDE/SQL box
-I am able to connect (my login) via Catalog
-SQL is set to OS and DB auth - I prefer OS
-...
When I try to register my database via ArcGIS Server Manager with me logged in (DBO access, Local Admin acces, ...) I get: "Invalid database connection"
I have a ticket open with ESRI, but thought I'd post it here too. What am I missing.