Description of problem:

Race in perftest indicates messages may be out of sequence. Not clear if this 
is a problem with the broker, the client or the test itself. Run in a loop as
follows:

[aconway@file-18 tests]$ while  ./perftest --count 100000 -s ; do true; done

Controller exception: Bad data, expecting double: Out-of-sequence messages
(perftest.cpp:239)

Version-Release number of selected component (if applicable):
svn revision 603037

How reproducible:

In an optimized build on file-18 (an 8 core server) it happens reliably within
10 runs or so. I have not reproduced it on any other box or with a debug build.

Additional info:

The error is caused by the controller receiving a non-numerical "out of order"
report from a subscriber.