Overriding android:ellipsize on ActionBar subtitle

My activity makes use of the ActionBar.setSubtitle function to display the currently displayed file system location's full path. This means that the substring towards the end of the subtitle is more relevant than the beginning, so I thought I would override the ActionBar style to ellipsize text at the start, rather than the end, like so:

res/values/themes.xml

<style name="Theme.Holo" parent="android:Theme.Holo">

    <!-- Action bar styles -->

    <item name="android:actionBarStyle">@style/Widget.Holo.ActionBar</item>

</style>

res/values/styles.xml

<style name="Widget.Holo.ActionBar" parent="@android:style/Widget.Holo.ActionBar">

    <item name="android:subtitleTextStyle">@style/TextAppearance.Holo.Widget.ActionBar.Subtitle</item>

</style>



<style name="TextAppearance.Holo.Widget.ActionBar.Subtitle"

       parent="@android:style/TextAppearance.Holo.Widget.ActionBar.Subtitle">

    <item name="android:ellipsize">start</item>

</style>

When I install this onto my ICS device (Nexus S), the text is still (incorrectly) ellipsized at the end. If I modify my version of TextAppearance.Holo.Widget.ActionBar.Subtitle to include an item for android:textSize , the subtitle's text size does get altered accordingly, so it would seem as if I am poking around in the right style; I just can't figure out why it's not honouring my android:ellipsize override.

To put all this into a question format: how can I override, using styles/themes, the android:ellipsize property of the subtitle view in the ActionBar ?