"Thread blocked indefinitely" kills the program despite being caught

Perhaps this is just me misunderstanding the semantics of exceptions, but the following program:

import Test.HUnit.Lang
import Control.Concurrent.STM

import Control.Exception

import Control.Concurrent
import Control.Concurrent.MVar

main = do
  mv <- newEmptyMVar
  forkIO $ do
        r <- performTestCase (atomically retry)
        print "Yeaahh!"
        print r
        evaluate r
        putMVar mv r
  print "Cool, let's see what we get"
  r <- takeMVar mv
  print r
  print "Am I printed?"

Should in my opinion, when run, print "Am I printed". This is because the "Thread blocked indefinitely" exception is caught by HUnit. However, this happens instead:

mbolingbroke@mb566 ~/Junk
$ ./Repro 
"Cool, let's see what we get"
"Yeaahh!"
Just (False,"thread blocked indefinitely")
Repro: thread blocked indefinitely

NB: I get the expected behaviour if I run it within GHCi, but not if I compile the program.

This is causing problems for test-framework (see http://bsp.lighthouseapp.com/projects/15661-hs-test-framework/tickets/1-exits-immediately-on-thread-blocked-indefinitely-exception#ticket-1-2)