Try this link and look for CreateFolder2 (it should work on fmp12 after conversion)
It should give you clues as to how to "unzip" a file after export.
What happens if you check the box for "Automatically open file" in the "Specify output file" dialog of the Export Field Contents script step?
This should make the Send Event step redundant.
This ended up working for me, thanks! Sorry it took a whilte to get around to marking it as correct.