I had a similar problem, when the guys behind me said their eyes were watering with the fuel burn from the bike, they couldn't get past me through the corners!!! I resolved mine with adjusting the fuel mixture screw adjuster on the side of the ECU (behind the rubber grommet). Don't adjust this screw unless you can use a four gas analyser in a garage (used for MOT emmisions testing). Is the exhaust a little sooty at the end pipes? Has the exhaust or airbox/filter been modded? These can effect the mixture, so too can a faulty or poorly adjusted sensor for fuel mapping, so check them first with a volt/resistance meter (using the guidance from the workshop manual). If they all check OK then go for the fuel mix screw.
If you dont know if yours has been adjusted then this is what you do: first, find a four gas analyser, used for testing emmissions gasses at the tailpipe of a car. get the bike at normal operating temp and put the tester in one of the pipes. Stock setting for emmision is 1.5% CO. Thats for both pipes/cyl. For a race bike,4% or even 6% are sometimes used. But for a street bike somewhere between 1.5% and 3.0% is best. If you dont use a gas analysere to adjust this setting youll NEVER get it right. I dont care what anyone else here says, you wont! Find a car shop or a bike shop that has this devise and ask if you can use it. If you have to pay an hours labour rate to do so its worth it! Remember, you're shooting in the dark if you dont know whats coming out of them pipes! Hope this helps