Volvo S40 1.6 Diesel issue

[MarssinS40]

Hi guys
Last 11 months I am an owner of S40 1.6 diesel 57reg (67 000 miles on the clock right now). I did notice 2 problems (if i can call it like that) with my engine so far.
Firstly, when i am breaking in idle speed (for instance just before traffic lights or when i am parking) i can feel engine is vibrating strongly before car fully stop and revs drop down a bit. I feel it quite strong on break pedal and steering wheel. When i release brake pedal during the vibrations, before car stops fully the vibration will stop. If i hold break pedal down until car fully stops, vibrations stop itself after we say 2 sec and rpm are going back up (during those 2 sec i am still holding the pedal down). This is not happening every time when i am breaking. But more often. And another thing is, that when i do exactly same process as i described above but with clutch pedal pushed down, the car stopping smoothly, with no vibrations at all.

Secondly, when i hold my foot on acceleration pedal softly, i mean i am trying to keep constant speed with really very soft touch on pedal, the car is juddering quite badly. Mostly in town, we say at speed limit around 20 or 30miles/hour. I am noticing this in the last few weeks. I actually did not feel that juddering when driving on motorways.
Hope that make sence to you and you can give me some advice and opinions pls. I asked at my local volvo dealer but did not get any serious answer from the guy. Actually he never heard about it.