Well obviously there is yet another 'disconnect' in procedures...
Restrictions on arrivals and departure tracks/procedures (SIDS and STARS) should always be met; unless specifically cancelled; but you can't just bust your assigned level...
Controllers should be aware of the height restrictions etc and give pilots appropriate time to get them flown; in the event that a controller won't be able to get them down due traffic etc they should be telling the PIC to cancel the arrival, or at least the appropriate height restriction; not just leave the likes of baobab72 hanging wondering what he should do.
I think the above circumstances is typical and poor technique applied by the ATC and is generally brought about by the lack of understanding of the other persons role.
Boabab72 given those circumstances I would have stated unable to meet the FL170 requirement when given the descent to FL150 in an attempt to clarify if it was needed or could be cancelled. If it was needed much better to unfortunately increase to 4000fm than dealing with a possible RA and paperwork generated a short-time later. Many SIDS and STARS are integrated such that one height restriction is directly related to the others (unders and overs) and are normally only a few miles from the actual crossing point so failure to meet theses potentially safety critical restrictions can mean bad news all around.