CFCache dynamic user content and flush whole region or specific cache object ids.

Hi there... looking through the documentation I am currently having difficulty working out the standard way of achieving my requirements.

I have a menu which is dynamic depending on the user and I would like to cache it.

I would then like to be able to either flush the cache for a specific user or for all users at once.

I was hoping I could wrap the navigation cfml in a cfcache tag such as

<cfcache key="NavCache" id="id#USERID#"   >

</cfcache>

I could then use the cacheRemoveAll function to clear the "NavCache" region and up this point everything is working great.

The problem occurs when I then attempt to flush a specific cache object by id.

I have tried cacheRemove method and the <cfcache> tag with the action="flush" attribute....however I have had no success.

First off... am I going about this in the wrong way ?

If I am along the right lines... what am I doing wrong?

Thanks very much