I tested this by running a simple job with the following options on emr.

--jobconf mapred.jobtracker.maxtasks.per.job=1 --hadoop-version 0.18 --ami-version 1.0

There were no errors. Are there any other tests you would like to suggest? 
What would I need to do to reproduced the problem that you were seeing that made you move that block to the end of the function?