If your model is in the following list you can change the software via "flash load". I don't know what it costs anymore but used to be around £100. [list=1]UMF003 - 900ss 1998/9, Slip-on Mufflers
UMF005 - 900ss 1998/9, Slip-on Mufflers and Modified Cam Timing
UMF007 - 900ss 1998/9, 944cc kit, DP cams,valves, Slip-on Mufflers
UMF013 - 900ss 2000, Slip-on Mufflers
UMF015 - 900ss 2000, Slip-on Mufflers and Modified Cam Timing
UMF021 - 750ss 1998/0, Slip-on Mufflers
UMF031 - 750ss 2000, Slip-on Mufflers
UMF043 - Monster 900ie 2000, Slip-on Mufflers
UMF045 - Monster 900ie 2000, Slip-on Mufflers , Modified Cam Timing
UMF051 - 900ss 2001, Slip-on Mufflers
UMF055 - 900ss 2001, Slip-on Mufflers and Modified Cam Timing
UMF061 - 900ss 2002, Slip-on Mufflers
UMF065 - 900ss 2002, Slip-on Mufflers and Modified Cam Timing[/list=1]
Have a look here:
http://www.fuelinmoto.com.au/fimnews.html#FLA You may have to replace your ECU with a programmable one in which case the power commander is the less expensive option. I'd definitely get the mapping checked as these bikes tend to run lean to pass emissions. Speak to someone like Nelly (on this board) who know a lot more than me.
[Edited on 28-3-2006 by Felix]