I currently have Froyo 2.2 on my Captivate. I can't seem to find anything on how to root it, all rooting instructions are for pre 2.2. All my rooting attempts have failed, 2.2 needs an updated root.zip file that I can't seem to find.
Download mode is now different with 2.2, also no luck here.
I don't have a recommendation for this, but I am wondering how you got 2.2 without rooting.
You don't have to be rooted to install Froyo. Froyo is installed using Odin one click if you don't have root. If you are rooted you can use Rom manager and install a zip by several cooks that have included froyo in their Rom.
I am having a similar problem. I have FROYO installed using ODIN. I tried different methods to root but I keep getting this error no matter the root method: E: Signature Verification Failed. Installation Aborted.