I think this is a Contribute bug, because I have found that the first time I
got to edit a page with a CF header everything looks great and the second time
the CSS is not applied.

So, my (pain in the butt) workaround is to do the following:

<cfinclude template="../resourceFiles/header.cfm">
<link href="../resourceFiles/css/users.css" rel="stylesheet" type="text/css" />
<cfinclude template="../resourceFiles/header2.cfm">