Coldfusion: Leading Space Bug

I swear, this function returns an undetectable leading space.

If I pass the function to a mid, and start at char 2, it starts on char 2 of the non-leading space version.  Yet if I surrond the function like this
 [#func#]

there is space between the first [ and the beginning of the ourput.  No lie.  I swear to god.  I even tired this:
 #mid(f_publish_news_get_filename(11),2,len(f_publish_news_get_filename))#

and it returned it as if there was no leading space.  Here is the function:

<cffunction name="f_publish_news_get_filename" returntype="string">

      <cfargument name=id default="0">

      <cfset var q1 = querynew("")>
      <cfset var str = "">

      <cfif id EQ 0>

            <cfreturn 0>

      <cfelse>

            <cfquery name=q1 datasource=dramanet>
            SELECT id, posted_date FROM news WHERE id = #id#
            </cfquery>

            <cfset str = trim("#q1.posted_date##q1.id#.html")>

            <cfreturn str>

      </cfif>

</cffunction>