Wet weather and adverse exchange rates put a dampener on the first half performance of do-it-yourself retailer Kingfisher.Sales in the 26 weeks to July 28th were down 3.3% to £5,478m from £5,662m at the interim stage last year. That was in line with market forecasts. On a constant currency basis, sales were up 1.0% but on a like-for-like (LFL) basis were off 2.8%.Adjusted pre-tax profit slumped 15.5% to £371m from £439m the year before, with the company sizing the impact of wet weather in the UK and Northern Europe at more than £30m, which might account for why the profit figure was £24m shy of the forecast by Charles Stanley. Statutory profit before tax fell 16.9% to £364m from £438m the year before. The interim dividend has been hiked by 25.1% to 3.09p from 2.47p last year.An updated version of this item is now available JH