API testing case from within a rails app

After upgrading from rails 2.3.3 to rails 2.3.8, i've lost the ability
to parse xml parms sent via tests using @request.env['RAW_POST_DATA'] =

Rails stopped parsing the content of the raw_post_data into params which
made all the test that depend on this fail. I'm also setting
@request.accept = "text/xml"

Anyone out there ended with something similar?