Clutch dipping and 5th gear noise

Hi all I have a 2005 Octavia 1.9tdi PD 4x4 and  when I am driving it sometimes feels like the clutch pedal is depressing itself by a small amount, this seems to happen when I am slowing down, does anyone know what this might be or what the possible cause could be??

Also when im in 5th gear and I take my foot of the accelator it sounds like there is a minor metalic grinding noise? it seems to be when im travelling at around 60mph and the take my foot off the gas to loose a bit of speed when coming in to a bend for example. I dont get it with any other gear except 5th, again any ideas???