Issue with car rolling sometimes

[Tyler]

Hi Guy's and Girls,

I brought my misses a 2004 Blob a little while back and I have noticed that sometimes the car has a issue rolling at low speed (Under 10mph) I did a little test the other day at a level crossing that had a slight gradient. I put the car into 1st, drove slowly up the hill and left it in gear with the clutch pedal down and the car did not roll back, I then put the car into natural and let go of the pedal and the car rolled back. Then when I drove off it felt as if the brake was on slightly but then it made a release noise as if you were trying to drive away with the handbrake on then you released it. It did the same when I was reverse parking on full lock. Does this sound like a possible gearbox/diff issue? I really hope it isn't. Would a gearbox and diff oil change make any difference as box is on 122k.
I did think it may be a possible calliper issue but it happened without touching the brakes.

[BIG"E"]

Does it have DCCD ?