Yes, when there is considerable distance up to the offer, many brokers will not allow a bid that exceeds a certain percentage gain, as they will be queried by the ASX.
To get around this, place a buy order lower down and leave it there for a period (say at least half an hour - roughly - preferably an hour or so), then if the order remains, amend the order to take out the bid and it will (should) execute. This way when the ASX question the broker about the large percentage gain (and they will), they can say no sellers would come down to meet the bid, so it was amended to buy the offer.
