Ant Exec task- getting back execution value into resultproperty

Hi,
I am using CruiseControl over Ant and I am running an Exec task that
runs a perl script that returns at exit "0" or "1" to determine
execution status.
My problem is that the resultproperty that suppose to get the returned
code does not change after execution.

The Exec task looks like that:
<property name="BuildStatus" value="123"/>
<echo message="Build status before=${BuildStatus}" />
<exec executable="perl"
failonerror="false"
failifexecutionfails="false"
resultproperty="${BuildStatus}"
output="output.txt"
dir="/scripts/">
<arg line="BuildAll.pl" />
</exec>
<echo message="Build status after=${BuildStatus}" />

The perl script ends with the following line:
exit($retVal);

When $retVal is initialized to 0 and can get the value of 0 or 1 only.

On the 2 prints surrounding the exec task I get the same value of
${BuildStatus} which is the one it was initialized with (123).
I tried initializing the property in the start of the Ant build file.
same results.
I tried using the attributes: outputproperty and errorproperty in order
to catch the return code. It didn't helped.

my purpose with this, is to fail the build at the end of it based on
the value returned from the perl script.

Ant-1.6.5
CruiseControl- 2.5.0
Java-1.5.0_06
Platform- MacBook, 1.83 Duo, 1GB Ram

Thanks,
Itai Barami.

.