Bluetooth chip specialist CSR is the best performer on the FTSE 250 after it questioned the recent results of US merger partner Zoran. The US peer said it is forecasting second quarter sales of $80-85m, down from a previous prediction of between $95-97m, after a disappointing first quarter. CSR said it has noted Zoran's latest guidance and is "currently evaluating the implications of these disclosures."Meanwhile, retailing peers Sports Direct, Dunelm, Carpetright and JD Sports are the biggest fallers.The share price of software specialist Micro Focus was helped after group said revenues and earnings for the year ended 30 April will be in line with consensus. Casino and bingo hall operator Rank is higher after advising its shareholders against accepting a 150p a share offer for the company from Guoco, saying it "significantly undervalues Rank and its prospects."Data centre operator Telecity is lower despite confirming its positive outlook for the year ahead.Builders' merchant Travis Perkins said revenue rose 5.9% for the four months ended April 2011 as it gained a bigger market share. Nevertheless, the share price is on the decline.Travel company Thomas Cook is lower after saying that unrest in the Middle East and North Africa has cost the firm £22m in the first half, whilst the shift of Easter had an impact of around £15m.---BCFTSE 250 - RisersCSR (CSR) 376.90p +6.17%Misys (MSY) 332.40p +4.86%Kenmare Resources (KMR) 43.67p +3.48%Micro Focus International Plc (MCRO) 384.90p +3.25%Kesa Electricals (KESA) 141.10p +2.92%Rank Group (RNK) 152.50p +2.49%Laird (LRD) 146.10p +2.03%Morgan Crucible Co (MGCR) 316.10p +1.97%Spirent Communications (SPT) 140.50p +1.96%Hunting (HTG) 766.00p +1.93%FTSE 250 - FallersSports Direct International (SPD) 194.50p -3.90%Dunelm Group (DNLM) 462.20p -3.08%Carpetright (CPR) 660.00p -2.94%JD Sports Fashion (JD.) 885.00p -2.75%Telecity Group (TCY) 517.50p -2.54%Brown (N.) Group (BWNG) 284.70p -2.50%Thomas Cook Group (TCG) 166.50p -2.40%Derwent London (DLN) 1,727.00p -2.32%Yule Catto & Co (YULC) 208.20p -2.25%Talvivaara Mining Company (TALV) 488.90p -2.16%