Reg-ex help

Hey guys, I'm trying to write a regular expression to match a tag for my frameworks template engine. I seem to be having some trouble. The expression should match: {:seg 'segname':} {:seg 'segname' cache:} What I have is... $fSegRegEx = "#\{:seg \'[a-z0-9\-\_]{3,}\'( cache)?:\}#i"; Which when run against my test data, seems to match: "{:seg 'segname' cache:}" " cache" For arguments sake, I'll provide the whole code snippet... preg_match($fSegRegEx, $this->msOpCont, $faSegMatches); /* faSegMatches ==

    * array

    * 0 => '{:seg 'users_online' cache:}'//

    * 1 => ' cache'//

    */

     while ( $fMatch = current($faSegMatches) ) {

       /* 
        * Expected:

        * $fMatch[0] = "{:seg "

        * $fMatch[1] = Segment Name

        * 
        * $fMatch[2] = " cache:}"

        * or

        * $fMatch[2] = " :}"

        */

       $faMatch  = explode("'", $fMatch);

       //...

       //...

       next($faSegMatches);

     }// End While

Thanks guys. This has been bugging me for a couple days. - Craige