well alot of older games (made prior to iXtreme v1.0) wont work on newer firmwares (i.e. iXtreme v1.0 or newer)
it's best to rerip from original disc and then check it with 'abgx360 v1.0.1' application here... http://xrl.us/bers9k ( this makes sure you backup's are properly made up to the best thats currently known ... and using that is pretty much required if you plan on using backup's on xbox live... otherwise you risk getting banned on xbox live )
just use ImgBurn for general xbox360 burning... just load the .dvd file and burn @ 4x (or 2.4x in some cases) or manually setup the layer break point to 1,913,760 and then you can directly burn the .iso file.
it's also strongly recommended to ONLY use Verbatim DVD+R DL (made in singapore) media if possible.
also, the latest firmware is iXtreme v1.51