ProtectedSource config doesn't work properly inside attributes

[fournaise]

When using Smarty protection source in FCKEditor 2.6beta :

FCKConfig.ProtectedSource.Add( /<\{[\s\S]*?\}>/g );
FCKConfig.ProcessHTMLEntities	= false ; //true

The following code is broken when swithing between wysiwyg/source edition :

<p><a href="{if $a=1}url1.htm{else}url2.htm{/if}">TEST</a></p>
<p>{if $a=1}url1.htm{else}url2.htm{/if}</p>

become :

<p><a href="%7Bif%20$a=1%7Durl1.htm%7Belse%7Durl2.htm%7B/if%7D">TEST</a></p>
<p>{if $a=1}url1.htm{else}url2.htm{/if}</p>

conclusion: Smarty code is protected only in tag and not in attribute.

Is it a bug ? how to avoid this behavior ?

[fournaise]

The problem occurs only with src and href attributes.