Hi !

When doing some tests related to #342, I ended up with this backtrace:
{{{
2010/03/26 02:10:00 [threads:1] Thread "wallclock_main" aborts with exception File "stream/aFrame.ml", line 31, characters 4-10: Assertion failed!
Thread 5 killed on uncaught exception Assert_failure("stream/aFrame.ml", 31, 4)
Called from file "outputs/ao_out.ml", line 82, characters 16-36
Called from file "tools/ioRing.ml", line 226, characters 4-34
Called from file "outputs/output.ml", line 221, characters 6-27
Called from file "list.ml", line 69, characters 12-15
Called from file "clock.ml", line 78, characters 4-41
Called from file "clock.ml", line 194, characters 10-24
Called from file "tools/tutils.ml", line 134, characters 15-18
Re-raised at file "tools/tutils.ml", line 157, characters 21-22
Called from file "thread.ml", line 38, characters 8-14
}}}

I do not really understand the issue so far, but I hope the trace can be helpful..