it worked for me.
okay, just adding my 2-cents, because I finally rooted the damn thing (sch-i800). if it works give me a thank you, note, or whatever.
I am using Heimdall 1.3.2 and had all kinds of problems. Most of these are dealing with the error code 12.
So here is what i did different.
I used the Utilities tab on Heimdall, downloaded the stock PIT off my Verzion Tab, and used that when flashing all the other files.
I only wanted Root so I used my own PIT, and the zImage from this thread.
Bingo, I now have root.
Now its time to add goodies (or more likely soft brick it a few times till I get it right.)