how to compile MXML module with ANT‏

Hi, I'm experiencing a problem and it has me completely baffled.

BTW: sorry if you receive this twice. I accidentally sent it to the old flex-users [ at ] incubator... list... I'm posting again here to make sure I do in fact get my question out to the community.

I have a project using flex4.5.1A

it has many modules.

I have set up an ant script with builds the main swf perfectly.

I'm now trying to set up the building of the modules.

I have the module defined as such:

<?xml version="1.0" encoding="utf-8"?>
<s:Module xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
implements="com.------.modules.IVolatileAssets"
width="400" height="300"
creationComplete="onDummy(event)"

the interface IVolatileAssets is in the same package as the module itself. In FlashBuilder this compiles perfectly. It works perfectly too. we have it IN PRODUCTION TODAY and millions of ppl use it daily.

when I use the following ANT build script:

<macrodef name="buildModule">
<attribute name="module-name" default="none" />
<attribute name="module-package" default="none" />
<attribute name="out-path" default="." />
<sequential>
<echo message="building @{module-name} to @{out-path}/@{module-name}.swf" />
<mxmlc file="${APP_ROOT}/src/@{module-package}/@{module-name}.mxml"
output="${DEPLOY_DIR}/@{out-path}/@{module-name}.swf"
keep-generated-actionscript="false"
incremental="false"
debug="true"
load-externs="${ANT_ROOT}/link-report.xml"

<load-config filename="${FLEX_HOME}/frameworks/flex-config.xml"/>
<source-path path-element="${FLEX_HOME}/frameworks"/>
<source-path path-element="${APP_ROOT}/src/@{module-package}"/>
<source-path path-element="${APP_ROOT}/src/@{module-package}/interfaces"/>
<compiler.library-path dir="${HOF_COMMON_ROOT}" append="true">
<include name="bin"/>
</compiler.library-path>
<compiler.library-path dir="${APP_ROOT}" append="true">
<include name="libs"/>
</compiler.library-path>
<compiler.library-path dir="${FLEX_HOME}/frameworks" append="true">
<include name="libs" />
<include name="../bundles/{locale}" />
</compiler.library-path>
<source-path path-element="${APP_ROOT}/src/locale/{locale}"/>
</mxmlc>
</sequential>
</macrodef>

<target name="modulesDebug" depends="lobbyDependencies" description="Build the lobby modules for debug">
<buildModule module-name="VolatileAssets" module-package="com/-----/modules" out-path="modules3"/>
</target>

i get the following error:

[mxmlc] F:\var\projects\hof\svn2.------.com\lobby\branches\3.1.39.0\src\com\hof\lobby\modules\VolatileAssets.mxml(-1): Error: Interface IVolatileAssets was not found.
[mxmlc] <?xml version="1.0" encoding="utf-8"?>

BUILD FAILED
F:\var\projects\hof\svn2.--------.com\lobby\branches\3.1.39.0\build.xml:97: The following error occurred while executing this line:

I have redacted the lines where our URL is shown for obvious reasons. What I don't understand AT ALL is how this interface could not be found. it is in the same folder as my module file, and the mxmlc task does not have the -includes-sources option to force it to be included.

Am I missing something obvious?

Thank you in advance for any advice.