You don't need to buy a revision G stalk. The only difference is that one wire is routed differently.
On earlier revisions there is a yellow wire going to pin 5 and another going to pin 10.
On newer revisions, both the yellow wires go into pin 10 and pin 5 is left vacant.
All you need to do is remove wire from pin 5, cut off pin connector from the end, strip back a bit of insulation from yellow wire going to pin 10, solder wire that used to go to pin 5 onto exposed wire that goes to pin 10 and tape/heat shrink the new join and your done.
I had the same problem when installing my Mk6 MFSW into my Mk5. I too had the same symptoms and the same code when scanning using VCDS. I knew I needed the revision G stalk and bought one, but it was actually pinned wrong (it was the same as earlier revisions). It was a eBay one so I chose to re-pin my original stalk as the quality looked slightly better. Plus it means I've now got a new back up stalk.