Silverlight loads image from URL, but it doesn't display - xaml

Question

Behold the following XAML:
<Grid>
<HyperlinkButton x:Name="Link" Background="Green">
<Grid Background="Red">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="12" />
</Grid.RowDefinitions>
<Image x:Name="AvatarImage" Style="{StaticResource AvatarStyle}" Grid.Column="0" Grid.Row="0" />
<StackPanel Grid.Column="1" HorizontalAlignment="Stretch">
<TextBlock Text="New Topic" Style="{StaticResource ItemTypeStyle}" />
<TextBlock x:Name="Title" Style="{StaticResource HeadlineStyle}" TextWrapping="Wrap" />
<TextBlock x:Name="SubText" Style="{StaticResource TextStyle}" TextWrapping="Wrap" />
</StackPanel>
<TextBlock x:Name="TimeStampText" Grid.ColumnSpan="2" Grid.Row="1" Style="{StaticResource TimeStampStyle}" />
</Grid>
</HyperlinkButton>
In the user control's Loaded event, I call the following code:
var imageUrl = new Uri("http://coasterbuzz.com/Forums/UserAvatar.ashx?id=2");
AvatarImage.Source = new BitmapImage(imageUrl);
Looking at Firebug, the image is coming down the wire, but for some reason it's not displayed. Any guesses as to why? You'd probably like to see the styles, but note that if I remove the styles, nothing changes.

Answer 1

Ah, easy answer. Silverlight 2 doesn't support GIF.
There is a handful of solutions to convert the image serverside here: http://silverlight.net/forums/t/3883.aspx
The most official reason I can find:
Why the support for displaying a .gif
image is is missing? When it will be
added?
We don’t want to take the hit for
another codec. It may only be a little
bit of download time—but our mandate
is small and fast and every little bit
counts. We are also hesitant to
support .gif because it implies
support for animated .gif, which we
decided would have to be integrated
into our animation scheme somehow—and
that will be a lot of work.
Looking from Flash perspective, Flash
does not support .gif either. However,
as of present, this is something being
evaluated, but no date has been
announced
http://blogs.msdn.com/ashish/archive/2008/04/03/silverlight-roadmap-questions.aspx