Android ant build - won't load keystore

My ant build for a Flex air 3.0 project for android with native extensions returns this error message:

could not load keystore file (password may be incorrect)

I'm sure password, keystore file name and path are all correct. I've tried to change the keystore file location & path - project root, desktop, c:\certs - but the error message remains the same. I've tried paths with no whitespace in dir names. I've created new certs.

In build.properties my keystore is referenced like this:

KEYSTORE=C:\dev\projects\Certificates\AndroidCert.p12
STOREPASS=mypassword

The part of my build.xml that deals with the keystore looks like so:

    <java jar="${ADT.JAR}" dir="${APP_BUILD}" fork="true" failonerror="true">
        <arg value="-package"/>
        <arg value="-target"/>
        <arg value="apk"/>
        <arg value="-storetype"/>
        <arg value="PKCS12"/>
        <arg value="-keystore"/>
        <arg value="${KEYSTORE}"/>
        <arg value="-storepass"/>
        <arg value="${STOREPASS}"/>
        <arg value="${APK_NAME}"/>
        <arg value="${APP_XML}"/>
        <arg value="${APP_SWF}"/>
        <arg value="icons/"/>
        <arg value="-extdir"/>
        <arg value="${EXT_DIR}/"/>
    </java开发者_运维技巧>

Any help to explain the error is very much appreciated.

Run the command manually and check the output. Also check for trailing spaces in your properties file.