Screen blinking when using a webview with flash

Edit: I made a demo apk, so you can understand what I mean: http://cl.ly/3g0s1p030j243y0p3m2F

For my application, I want a kind of "Super Power Point", or a keynote (the commercial team will present the product to their customers) using all the Android goodness, gestures, etc... on an Android tablet. As Honeycomb is not yet ready and because we need it before march, we choose some random Froyo Tablet (Archos 101), but my issue is for every tablet/phone I tried.

I made a really great application, but for some animations during the presentation, the customer wanted to use flash animations. Because I couldn't code animations (sort of little movies/ animated graphics) that easily in Android and the lack of time, that seemed to be a good idea.

So, after some search on the Web, I used webview and this code:

    WebView mWebView1 = (WebView) findViewById(R.id.webview1);
    mWebView1.getSettings().setJavaScriptEnabled(true);
    mWebView1.getSettings().setPluginsEnabled(true);
    mWebView1.loadUrl("file:///android_asset/graph_01.swf");

This work pretty well, but on every device I tried (Archos 101, Nexus One, Nexus S, Galaxy S, Xperia, Desire, HTC Hero, and really more) every activity with a webview blink, a few milliseconds of black screen, then the animation finally appear.

PS: My layout is quite simple too:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<WebView android:id="@+id/webview1" android:layout_height="fill_parent"
            android:layout_width="fill_parent"></WebView>
</LinearLayout>

Please help me, I cannot imagine I am the only one to face this issue.

Thank a lot for any h