Ok thanks for that guys - question answered. Found this in the other thread that was particuarly useful -
"From NATS ATM Policy & Performance
A clearance issued with a restriction to be "level by" becomes null and void when a futher climb/descent clearance is issued before the original has been fully complied with. Where, according to Standing Agrrements, ATSUs are able to transfer aircraft in receipt of such conditional clearances, the receiving sector should be particularly cautious in issuing further climb/descent clearances. Further, controllers are reminded that any re-clearance instructions issued should also include the original climb/descent restiction where this is still required."
I take on board and agree with though the many points in favour of still making the restriction, and thus will continue trying to make it, which is how I've done it until now.
I guess good airmanship and situational awareness rules at the end of the day.
Cheers all
