HI
If that is the case the use of the IN/OUT markers may be version specific. In version 3.6 once you have "used" the green arrow to place your clip bit on the sequence,(set the options "Ask Me",so you can choose where they are added,) moving the the IN/OUT markers again has no effect. Even if you slide them both left of your initial selection as you suggest.
However, as I mentioned, with this version just re-selecting (left clcking) the clip in the media list will redisplay the clip, reset the geen arrow but leave the IN/OUT markers where they were and allow you select a different part of the clip (or the same section again) and repeat the procedure. It makes producing multiple repeating sections easy.
Nat