auto_explain causes regression failures

With the following settings

    custom_variable_classes = 'auto_explain'
    auto_explain.log_min_duration = 0
    auto_explain.log_format = 'xml'
    auto_explain.log_analyze = on
    auto_explain.log_verbose = on
    shared_preload_libraries = 'auto_explain'

I am getting regression failures on the rowtypes, transactions and 
arrays tests. Diff file is attached. I'm going to look into it, but if 
anyone has a good idea what's going on please speak up ASAP.

cheers

andrew