Those look pretty normal although the +12v is high. Of course things could be very different when your system is under normal or heavy usage and YES I agree that a 300W PSU is a little borderline with what you have running, esp if it isn't one of the better brands like Antec or Enermax (opinions obv vary). Someone else is having stability problems so you may want to check out ...
http://forums.hexus.net/showthread.php?threadid=1745