Android : Unable To Access R.id From Inside Custom View

In my foo_layout.xml file I have a subclassed RelativeLayout:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<com.android.myapp.FooView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/pegboard_table"
android:orientation="vertical"
android:scaleType="fitXY"
>
<ImageView
android:id="@+id/triangular"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/pegboard_board"
android:scaleType="fitXY"
android:gravity="center"
android:visibility="invisible"
/>
<Chronometer
android:id="@+id/timer"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/timer_display"
android:textSize="40sp"
android:textColor="#000"
android:layout_alignParentTop="true"
android:gravity="center"
android:visibility="invisible"/>
<TableLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/board_table"
android:visibility="invisible"
/>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:gravity="center_horizontal"
android:background="@drawable/tab_bar">
<!-- android:layout_alignLeft="@id/options_tab"-->
<ImageView
android:id="@+id/game_select"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:src="@drawable/game_select" android:paddingLeft="15sp"/>
<ImageView
android:id="@+id/undo_select"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@id/game_select"
android:layout_weight="1"
android:src="@drawable/undo"
/>
<ImageView
android:id="@+id/settings_select"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@id/undo_select"
android:layout_weight="1"
android:src="@drawable/settings"
/>
<ImageView
android:id="@+id/info_select"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@id/settings_select"
android:layout_weight="1"
android:src="@drawable/info"

This doesn't seem like the right behavior. I've tried it with other views inside the FooView hierarchy and findViewById() always returns null.

For the life of me I can't figure out what I'm doing wrong.