I've run into a strange bug with CFC inheritance.  It definitely seems to be a problem in ColdFusion 8, and I would be interested to see if it's a problem in CF9 also, but I haven't started using CF9 yet.

The problem comes up if you extend a CFC of the same name that is in a different directory.  CFCs in different directories should be treated as completely different components, as far as I know, but something goes wrong if the file name is the same.  For a simple test case, I created 3 CFCs:

/test/Test1.cfc
<cfcomponent output="false">
    <cffunction name="Test" output="true">
        Super Test
    </cffunction>
</cfcomponent>

/Test1.cfc
<cfcomponent extends="test.Test1" output="false">
    <cffunction name="Test" output="true">
        Test
    </cffunction>
</cfcomponent>

/Test2.cfc
<cfcomponent extends="test.Test1" output="false">
    <cffunction name="Test" output="true">
        Test
    </cffunction>
</cfcomponent>

The first file is in a subdirectory, and the other two files are identical except for their names -- one of them is the same name as the first file, and the other one is different.

I created a fourth file with the following code:

<cfset CFC1 = CreateObject("component","test.Test1")>
<cfset CFC2 = CreateObject("component","test.Test2")>
<cfoutput>
<p>#CFC1.Test()#</p>
<p>#CFC2.Test()#</p>
</cfoutput>

What would you expect this file to output?  I would expect:

Test
Test

Instead, I get:

Super Test
Test

In other words, even though /Test1.cfc overrides the Test function, it is ignored in favor of the function in /test/Test1.cfc.  Test2.cfc, on the other hand, works correctly.

My first question, of course, is: Have I missed something?  This sure seems like a glaring bug to me.

Update:
If the Test function is set to access="remote" and called directly from the browser like this:
/Test1.cfc?method=Test
Then it produces "Test" as expected.  All other methods I have tried of calling the function produce "Super Test".  Certainly a head-scratcher.