first, are you sure the location will be well lit? when it comes to photography, sports event are NEVER lit well enough, especially because you need to shoot with a fast shutter to freeze the action.
second, how come your flash is too bright? did you use the manual flash power override? that would explain it.
if you use flash in P mode (or A if thats the only thing the ixus has to offer) it should be adjusted automatically and should NOT turn out to be too bright. maybe you need another exposure setting, spot for example.
i would recommend shooting with flash on the 2nd curtain in A mode (if your cam allows it), freezing the subject and blurring the background.
sports photography is a very difficult subject, and if i learnt one thing during the last half year since i got my dslr: when comes to INSIDE locations, a P&S can never outperform a DSLR, especially when you are not allowed to use flash. Of course you need a fast lens.
