Pace's shares took a tumble on Tuesday after the set-top box maker revealed that first quarter profitability was lower than it expected due to higher-than-expected input prices.While this has led RBS to make material forecast downgrades on the "clearly disappointing news", the broker keeps its 'buy' rating, saying that share price decline looks overdone.The broker makes a 28% cut to 2011 operating profit (to £103.3m) and a 14% downgrade to 2012 expectations. Additionally, the target price is almost halved from 237p to 125p.However, the broker said "it is worth noting that volumes and revenues remain in line with management expectations."---BC