Random build failures

Good morning list.

At $work we have mod_perl built every night by our build system.  Even
though this is the same binary sometimes (but not always) it fails the
test:

t/apache/read3.t

Running this test again by hand (under t/TEST) succeeds.  It's got
nothing to do with the order in which the tests run since I've set

I was wondering if anyone had any experience of anything like this before?

Mark.

P.S.  In case it's important:

Ubuntu 10.4 LTS on intel
Perl 5.12.3
httpd-2.2.16

t/apache/read3.t ........................
Failed 1/1 subtests

Test Summary Report
-------------------
t/apache/read3.t                      (Wstat: 0 Tests: 0 Failed: 0)
  Parse errors: Bad plan.  You planned 1 tests but ran 0.
Files=242, Tests=2659, 744 wallclock secs ( 1.57 usr  2.54 sys +
104.00 cusr 28.49 csys = 136.60 CPU)
Result: FAIL