android.intent.action.SEND; doing it wrong?

So I'm updating an app I created a while ago. In the AndroidManifest.xml I have the following (along with an <intent-filter> for android.intent.action.MAIN) inside an <activity>:

<intent-filter android:label="@string/send_label" android:icon="@drawable/icon">
    <action android:name="android.intent.action.SEND" />
    <data android:mimeType="text/plain" />
</intent-filter>

If I remember correctly, when I first created this app, the above (minus the android:label and android:icon bits) worked; my app would show up in the "Share" menu. A couple weeks ago I noticed a review of my app on the Ma开发者_如何学Crket saying that it didn't show up when trying to Share stuff. I checked, and sure enough, it wasn't there.

Is the fact that I have two <intent-filter> blocks for one Activity confusing it? Did I break something between then and now, did something change in the Android API, or what's going on here?

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Don't you need to specify a category? (such as <category android:name="android.intent.category.DEFAULT" />