setting "forceplugins" to 1 results in garbled output

When the quiz setting "forceplugins" is enabled, our Hot Potatoe Quizzes with embedded mp3 files are completely garbled in the browser.

With "forceplugins" turned off, the quiz is displayed ok.

When I used the mediaplugin_filter of moodle version 1.6.3. it worked with "forceplugins" turned on.

the hotpot module seems to have problems, escaping the html code that is returned by the newer mediaplugin_filter() function.